Polymer templated nanowire catalysts

ABSTRACT

Nanowires useful as heterogeneous catalysts are provided. The nanowire catalysts are prepared by polymer templated methods and are useful in a variety of catalytic reactions, for example, the oxidative coupling of methane to ethane and/or ethylene. Related methods for use and manufacture of the same are also disclosed.

BACKGROUND Technical Field

This invention is generally related to novel nanowire catalysts and, more specifically, to nanowires prepared via polymer templated methods. The nanowires are useful as heterogeneous catalysts in a variety of catalytic reactions, such as the oxidative coupling of methane to ethylene.

Description of the Related Art

Catalysis is the process in which the rate of a chemical reaction is either increased or decreased by means of a catalyst. Positive catalysts increase the speed of a chemical reaction, while negative catalysts slow it down. Substances that increase the activity of a catalyst are referred to as promoters or activators, and substances that deactivate a catalyst are referred to as catalytic poisons or deactivators. Unlike other reagents, a catalyst is not consumed by the chemical reaction, but instead participates in multiple chemical transformations. In the case of positive catalysts, the catalytic reaction generally has a lower rate-limiting free energy change to the transition state than the corresponding uncatalyzed reaction, resulting in an increased reaction rate at the same temperature. Thus, at a given temperature, a positive catalyst tends to increase the yield of desired product while decreasing the yield of undesired side products. Although catalysts are not consumed by the reaction itself, they may be inhibited, deactivated or destroyed by secondary processes, resulting in loss of catalytic activity.

Catalysts are generally characterized as either heterogeneous or homogeneous. Heterogeneous catalysts exist in a different phase than the reactants (e.g. a solid metal catalyst and gas phase reactants), and the catalytic reaction generally occurs on the surface of the heterogeneous catalyst. Thus, for the catalytic reaction to occur, the reactants must diffuse to and/or adsorb onto the catalyst surface. This transport and adsorption of reactants is often the rate limiting step in a heterogeneous catalysis reaction. Heterogeneous catalysts are also generally easily separable from the reaction mixture by common techniques such as filtration or distillation.

In contrast to a heterogeneous catalyst, a homogenous catalyst exists in the same phase as the reactants (e.g., a soluble organometallic catalyst and solvent-dissolved reactants). Accordingly, reactions catalyzed by a homogeneous catalyst are controlled by different kinetics than a heterogeneously catalyzed reaction. In addition, homogeneous catalysts can be difficult to separate from the reaction mixture.

While catalysis is involved in any number of technologies, one particular area of importance is the petrochemical industry. At the foundation of the modern petrochemical industry is the energy-intensive endothermic steam cracking of crude oil. Cracking is used to produce nearly all the fundamental chemical intermediates in use today. The amount of oil used for cracking and the volume of green house gases (GHG) emitted in the process are quite large: cracking consumes nearly 10% of the total oil extracted globally and produces 200M metric tons of CO₂ equivalent every year (Ren, T, Patel, M. Res. Conserv. Recycl. 53:513, 2009). There remains a significant need in this field for new technology directed to the conversion of unreactive petrochemical feedstocks (e.g. paraffins, methane, ethane, etc.) into reactive chemical intermediates (e.g. olefins), particularly with regard to highly selective heterogeneous catalysts for the direct oxidation of hydrocarbons.

While there are multistep paths to convert methane to certain specific chemicals using first; high temperature steam reforming to syngas (a mixture of H₂ and CO), followed by stochiometry adjustment and conversion to either methanol or, via the Fischer-Tropsch (F-T) synthesis, to liquid hydrocarbon fuels such as diesel or gasoline, this does not allow for the formation of certain high value chemical intermediates. This multi-step indirect method also requires a large capital investment in facilities and is expensive to operate, in part due to the energy intensive endothermic reforming step. (For instance, in methane reforming, nearly 40% of methane is consumed as fuel for the reaction.) It is also inefficient in that a substantial part of the carbon fed into the process ends up as the GHG CO₂, both directly from the reaction and indirectly by burning fossil fuels to heat the reaction. Thus, to better exploit the natural gas resource, direct methods that are more efficient, economical and environmentally responsible are required.

One of the reactions for direct natural gas activation and its conversion into a useful high value chemical, is the oxidative coupling of methane (“OCM”) to ethylene: 2CH₄+O₂ →C₂H₄+2H₂O. See, e.g., Zhang, Q., Journal of Natural Gas Chem., 12:81, 2003; Olah, G. “Hydrocarbon Chemistry”, Ed. 2, John Wiley & Sons (2003). This reaction is exothermic (ΔH=−67 kcals/mole) and has typically been shown to occur at very high temperatures (>700° C.). Although the detailed reaction mechanism is not fully characterized, experimental evidence suggests that free radical chemistry is involved. (Lunsford, J. Chem. Soc., Chem. Comm., 1991; H. Lunsford, Angew. Chem., Int. Ed. Engl., 34:970, 1995). In the reaction, methane (CH₄) is activated on the catalyst surface, forming methyl radicals which then couple in the gas phase to form ethane (C₂H₆), followed by dehydrogenation to ethylene (C₂H₄). Several catalysts have shown activity for OCM, including various forms of iron oxide, V₂O₅, MoO₃, Co₃O₄, Pt—Rh, Li/ZrO₂, Ag—Au, Au/Co₃O₄, Co/Mn, CeO₂, MgO, La₂O₃, Mn₃O₄, Na₂WO₄, MnO, ZnO, and combinations thereof, on various supports. A number of doping elements have also proven to be useful in combination with the above catalysts.

Since the OCM reaction was first reported over thirty years ago, it has been the target of intense scientific and commercial interest, but the fundamental limitations of the conventional approach to C—H bond activation appear to limit the yield of this attractive reaction. Specifically, numerous publications from industrial and academic labs have consistently demonstrated characteristic performance of high selectivity at low conversion of methane, or low selectivity at high conversion (J. A. Labinger, Cat. Lett., 1:371, 1988). Limited by this conversion/selectivity threshold, no OCM catalyst has been able to exceed 20-25% combined C₂ yield (i.e. ethane and ethylene), and more importantly, all such reported yields operate at extremely high temperatures (>800 C).

In this regard, it is believed that the low yield of desired products (i.e. C₂H₄ and C₂H₆) is caused by the unique homogeneous/heterogeneous nature of the reaction. Specifically, due to the high reaction temperature, a majority of methyl radicals escape the catalyst surface and enter the gas phase. There, in the presence of oxygen and hydrogen, multiple side reactions are known to take place (J. A. Labinger, Cat. Lett., 1:371, 1988). The non-selective over-oxidation of hydrocarbons to CO and CO₂ (e.g., complete oxidation) is the principal competing fast side reaction. Other undesirable products (e.g. methanol, formaldehyde) have also been observed and rapidly react to form CO and CO₂.

In order to result in a commercially viable OCM process, a catalyst optimized for the activation of the C—H bond of methane at lower temperatures (e.g. 500-700° C.), higher activities and higher pressures are required. While the above discussion has focused on the OCM reaction, numerous other catalytic reactions (as discussed in greater detail below) would significantly benefit from catalytic optimization.

One type of catalyst expected to meet the above need are nanowire catalysts comprising various metal elements; however, methods for preparation of nanowire catalysts which fulfill these needs are not readily available in the art. Accordingly, there remains a need in the art for improved catalysts and, more specifically, a need for novel approaches to catalyst preparation and design for improving the yield of, for example, the OCM reaction and other catalyzed reactions. The present invention fulfills these needs and provides further related advantages.

BRIEF SUMMARY

As noted above, the present disclosure is directed to nanowires, in particular nanowires prepared via polymer template methods. The nanowires find utility as catalysts in any number of chemical reactions, for example in the oxidative coupling of methane. In one embodiment the disclosure provides a method for preparing a nanowire comprising a metal oxide, a metal oxy-hydroxide, a metal oxycarbonate or a metal carbonate, the method comprising:

a) providing a solution comprising a plurality of polymer templates;

(b) introducing at least one metal ion and at least one anion to the solution under conditions and for a time sufficient to allow for nucleation and growth of a nanowire comprising a plurality of metal salts (M_(m)X_(n)Z_(p)) on the template; and

(c) optionally converting the nanowire (M_(m)X_(n)Z_(p)) to a metal oxide nanowire comprising a plurality of metal oxides (M_(x)O_(y)), metal oxy-hydroxides (M_(x)O_(y)OH_(z)), metal oxycarbonates (M_(x)O_(y)(CO₃)_(z)), metal carbonate (M_(x)(CO₃)_(y)) or combinations thereof

wherein:

M is, at each occurrence, independently a metal element from any of Groups 1 through 7, lanthanides or actinides;

X is, at each occurrence, independently hydroxides, carbonates, bicarbonates, phosphates, hydrogenphosphates, dihydrogenphosphates, sulfates, nitrates or oxalates;

Z is O;

n, m, x and y are each independently a number from 1 to 100; and

p is a number from 0 to 100.

In certain embodiments of the foregoing method, the polymer template comprises PVP (polyvinlpyrrolidone), PVA (polyvinylalcohol), PEI (polyethyleneimine), PEG (polyethyleneglycol), polyethers, polyesters, polyamides, dextran, sugar polymers, functionalized hydrocarbon polymers, functionalized polystyrene, polylactic acid, polycaprolactone, polyglycolic acid, poly(ethylene glycol)-poly(propylene glycol)-poly(ethylene glycol) or copolymers or combinations thereof. For example, in some embodiments the polymer template is functionalized with at least one of amine, carboxylic acid, sulfate, alcohol, halogen or thiol groups, and in other embodiments the polymer template comprises a hydrocarbon polymer or a polystyrene polymer functionalized with at least one of amine, carboxylic acid, sulfate, alcohol, halogen or thiol groups.

In other embodiments, the method further comprises freeze drying the nanowire, and in some embodiments the solution comprising the polymer template is in the form of a gel, for example, some embodiments comprise a step of base treatment, for example base treatment of a gel, and precipitating at least one metal.

In other embodiments of the foregoing method, the method further comprises use of two or more different metal ions.

In another aspect, the present disclosure is directed to a method for preparing a nanowire comprising a metal oxide, a metal oxy-hydroxide, a metal oxycarbonate or a metal carbonate, the method comprises:

a) providing a solution comprising a plurality of a multifunctional coordinating ligands;

(b) introducing at least one metal ion to the solution, thereby forming a metal ion-ligand complex; and

(c) introducing a polyalcohol to the solution, wherein the polyalcohol polymerizes with the metal-ion ligand complex to form a polymerized metal ion-ligand complex.

In some embodiments, the multifunctional coordinating ligand is an alpha-hydroxycarboxylic acid. For example, in some embodiments the multifunctional coordinating ligand is citric acid.

In other embodiments, the polyalcohol is ethylene glycol or glycerol.

In some embodiments, the foregoing method comprises heating the polymerized metal ion-ligand complex to remove substantially all organic material, while in other embodiments, the method further comprises heating the polymerized metal ion-ligand complex to obtain a metal oxide.

In another embodiment, the disclosure provides a method for preparing metal oxide, metal oxy-hydroxide, metal oxycarbonate or metal carbonate catalytic nanowires in a core/shell structure, the method comprising:

(a) providing a solution that includes a plurality of polymer templates;

(b) introducing a first metal ion and a first anion to the solution under conditions and for a time sufficient to allow for nucleation and growth of a first nanowire (M1_(m1)X1_(n1)Z_(p1)) on the template; and

(c) introducing a second metal ion and optionally a second anion to the solution under conditions and for a time sufficient to allow for nucleation and growth of a second nanowire (M2_(m2)X2_(n2)Z_(p2)) on the first nanowire (M1_(m1)X1_(n1)Z_(p1));

(d) converting the first nanowire (M1_(m1)X1_(n1)Z_(p1)) and the second nanowire (M2_(m2)X2_(n2)Z_(p2)) to the respective metal oxide nanowires (M1_(x1)O_(y1)) and (M2_(x2)O_(y2)), the respective metal oxy-hydroxide nanowires (M1_(x1)O_(y1)OH_(z1)) and (M2_(x2)O_(y2)OH_(z2)) the respective metal oxycarbonate nanowires (M1_(x1)O_(y1)(CO₃)_(z1)) and (M2_(x2)O_(y2)(CO₃)_(z2)) or the respective metal carbonate nanowires (M1_(x1)(CO₃)_(y1)) and (M2_(x2)(CO₃)_(y2)),

wherein:

M1 and M2 are the same or different and independently selected from a metal element;

X1 and X2 are the same or different and independently hydroxides, carbonates, bicarbonates, phosphates, hydrogenphosphates, dihydrogenphosphates, sulfates, nitrates or oxalates;

Z is O;

n1, m1n2, m2, x1, y1, z1, x2, y2 and z2 are each independently a number from 1 to 100; and

p1 and p2 are independently a number from 0 to 100.

In certain embodiments of the foregoing, the polymer template comprises PVP (polyvinlpyrrolidone), PVA (polyvinylalcohol), PEI (polyethyleneimine), PEG (polyethyleneglycol), polyethers, polyesters, polyamides, dextran, sugar polymers, functionalized hydrocarbon polymers, functionalized polystyrene, polylactic acid, polycaprolactone, polyglycolic acid, poly(ethylene glycol)-poly(propylene glycol)-poly(ethylene glycol) or copolymers or combinations thereof. For example, in some embodiments the polymer template is functionalized with at least one of amine, carboxylic acid, sulfate, alcohol, halogen or thiol groups, and in other embodiments the polymer template comprises a hydrocarbon polymer or a polystyrene polymer functionalized with at least one of amine, carboxylic acid, sulfate, alcohol, halogen or thiol groups. In other embodiments, M1 and M2 are different.

In still other embodiments, the disclosure provides a method for preparing a catalytic nanowire, the method comprising:

admixing (A) with a mixture comprising (B) and (C);

admixing (B) with a mixture comprising (A) and (C); or

admixing (C) with a mixture comprising (A) and (B) to obtain a mixture comprising (A), (B) and (C), wherein (A), (B), and (C) comprise, respectively:

(A) a polymer template;

(B) one or more salts comprising one or more elements selected from Groups 1 through 7, lanthanides and actinides and hydrates thereof; and

(C) one or more anion precursors.

In certain embodiments of the foregoing, the mixture comprising (B) and (C) has been prepared by admixing (B) and (C), the mixture comprising (A) and (C) has been prepared by admixing (A) and (C) or the mixture comprising (A) and (B) has been prepared by admixing (A) and (B).

In other embodiments, the one or more salts comprise chlorides, bromides, iodides, nitrates, sulfates, acetates, oxides, oxalates, oxyhalides, oxynitrates, phosphates, hydrogenphosphate, dihydrogenphosphate or mixtures thereof. For example, the one or more salts comprise MgCl₂, LaCl₃, ZrCl₄, WCl₄, MoCl₄, MnCl₂ MnCl₃, Mg(NO₃)₂, La(NO₃)₃, ZrOCl₂, Mn(NO₃)₂, Mn(NO₃)₃, ZrO(NO₃)₂, Zr(NO₃)₄ or mixtures thereof. In other embodiments, the one or more salts comprise Mg, Ca, Mg, W, La, Nd, Sm, Eu, W, Mn, Zr or mixtures thereof.

In some embodiments, the one or more anion precursors comprises alkali metal hydroxides, alkaline earth metal hydroxides, carbonates, bicarbonates, ammonium hydroxides, or mixtures thereof. For example, in some embodiments the one or more anion precursors comprises LiOH, NaOH, KOH, Sr(OH)₂, Ba(OH)₂, Na₂CO₃, K₂CO₃, NaHCO₃, KHCO₃, and NR₄OH, wherein R is selected from H, and C₁-C₆ alkyl.

In certain other embodiments of the above method, the polymer template comprises PVP (polyvinlpyrrolidone), PVA (polyvinylalcohol), PEI (polyethyleneimine), PEG (polyethyleneglycol), polyethers, polyesters, polyamides, dextran, sugar polymers, functionalized hydrocarbon polymers, functionalized polystyrene, polylactic acid, polycaprolactone, polyglycolic acid, poly(ethylene glycol)-poly(propylene glycol)-poly(ethylene glycol) or copolymers or combinations thereof. For example, in some embodiments the polymer template is functionalized with at least one of amine, carboxylic acid, sulfate, alcohol, halogen or thiol groups, and in other embodiments the polymer template comprises a hydrocarbon polymer or a polystyrene polymer functionalized with at least one of amine, carboxylic acid, sulfate, alcohol, halogen or thiol groups.

In other embodiments, the method further comprises allowing the mixture comprising (A), (B), and (C) to stand at a temperature of from about 4° C. to about 80° C. for a period of time sufficient to allow nucleation of the catalytic nanowires, and other examples further comprise adding a doping element comprising metal elements, semi-metal elements, non-metal elements or combinations thereof to the mixture comprising (A), (B), and (C).

Some embodiments comprise calcining the nanowires, for example in some embodiments calcining the nanowires comprises heating the nanowires at 450° C. or greater for at least 60 min.

In other embodiments, the method further comprises doping the nanowires, wherein doping the nanowires comprises contacting the nanowires with a solution comprising a dopant and evaporating any excess liquid, wherein the dopant comprises a metal element, a semi-metal element, a non-metal element or combinations thereof.

In another embodiment, the disclosure provides a method for preparing metal oxide nanowires, the method comprising:

(a) providing a solution comprising a plurality of polymer templates; and

(b) introducing a compound comprising a metal to the solution under conditions and for a time sufficient to allow for nucleation and growth of a nanowire (M_(m)Y_(n)) on the template;

wherein:

M is a metal element from any of Groups 1 through 7, lanthanides or actinides;

Y is O,

n and m are each independently a number from 1 to 100.

In some embodiments of the foregoing, the polymer template comprises PVP (polyvinlpyrrolidone), PVA (polyvinylalcohol), PEI (polyethyleneimine), PEG (polyethyleneglycol), polyethers, polyesters, polyamides, dextran, sugar polymers, functionalized hydrocarbon polymers, functionalized polystyrene, polylactic acid, polycaprolactone, polyglycolic acid, poly(ethylene glycol)-poly(propylene glycol)-poly(ethylene glycol) or copolymers or combinations thereof. For example, in some embodiments the polymer template is functionalized with at least one of amine, carboxylic acid, sulfate, alcohol, halogen or thiol groups, and in other embodiments the polymer template comprises a hydrocarbon polymer or a polystyrene polymer functionalized with at least one of amine, carboxylic acid, sulfate, alcohol, halogen or thiol groups.

The present disclosure also provides a nanowire prepared according to any of the foregoing methods and in other embodiments provides a catalytic material comprising the same.

Other embodiments provide a method for the preparation of a downstream product of ethylene, the method comprising converting methane into ethylene in the presence of a nanowire prepared according to any of the foregoing methods or a catalytic material comprising the same, and further oligomerizing the ethylene to prepare a downstream product of ethylene.

In another embodiment, a process for the preparation of ethylene from methane comprising contacting a mixture comprising oxygen and methane at a temperature below 900° C. with a nanowire prepared according to any of the foregoing methods or a catalytic material comprising the same is provided.

These and other aspects of the invention will be apparent upon reference to the following detailed description. To this end, various references are set forth herein which describe in more detail certain background information, procedures, compounds and/or compositions, and are each hereby incorporated by reference in their entirety.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

In the drawings, the sizes and relative positions of elements in the drawings are not necessarily drawn to scale. For example, the various elements and angles are not drawn to scale, and some of these elements are arbitrarily enlarged and positioned to improve drawing legibility. Further, the particular shapes of the elements as drawn are not intended to convey any information regarding the actual shape of the particular elements, and have been selected solely for ease of recognition in the drawings.

FIG. 1 schematically depicts a first part of an OCM reaction at the surface of a metal oxide catalyst.

FIG. 2 shows a high throughput work flow for synthetically generating and testing libraries of nanowires.

FIG. 3 illustrates a nanowire in one embodiment.

FIG. 4 illustrates a nanowire in a different embodiment.

FIG. 5 illustrates a plurality of nanowires.

FIG. 6 is a flow chart of an exemplary nucleation process for forming a metal oxide nanowire.

FIG. 7 is a flow chart of an exemplary sequential nucleation process for forming a nanowire in a core/shell configuration.

FIG. 8 schematically depicts a carbon dioxide reforming reaction on a catalytic surface.

FIG. 9 is a flow chart for data collection and processing in evaluating catalytic performance.

FIG. 10 illustrates a number of downstream products of ethylene.

FIG. 11 depicts a representative process for preparing a lithium doped MgO nanowire.

FIG. 12 depicts OCM and ethylene oligomerization modules.

DETAILED DESCRIPTION OF THE INVENTION

In the following description, certain specific details are set forth in order to provide a thorough understanding of various embodiments. However, one skilled in the art will understand that the invention may be practiced without these details. In other instances, well-known structures have not been shown or described in detail to avoid unnecessarily obscuring descriptions of the embodiments. Unless the context requires otherwise, throughout the specification and claims which follow, the word “comprise” and variations thereof, such as, “comprises” and “comprising” are to be construed in an open, inclusive sense, that is, as “including, but not limited to.” Further, headings provided herein are for convenience only and do not interpret the scope or meaning of the claimed invention.

Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Also, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the content clearly dictates otherwise. It should also be noted that the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise.

As discussed above, heterogeneous catalysis takes place between several phases. Generally, the catalyst is a solid, the reactants are gases or liquids and the products are gases or liquids. Thus, a heterogeneous catalyst provides a surface that has multiple active sites for adsorption of one more gas or liquid reactants. Once adsorbed, certain bonds within the reactant molecules are weakened and dissociate, creating reactive fragments of the reactants, e.g., in free radical forms. One or more products are generated as new bonds between the resulting reactive fragments form, in part, due to their proximity to each other on the catalytic surface.

As an example, FIG. 1 shows schematically the first part of an OCM reaction that takes place on the surface of a metal oxide catalyst 10 which is followed by methyl radical coupling in the gas phase. A crystal lattice structure of metal atoms 14 and oxygen atoms 20 are shown, with an optional dopant 24 incorporated into the lattice structure. In this reaction, a methane molecule 28 comes into contact with an active site (e.g., surface oxygen 30) and becomes activated when a hydrogen atom 34 dissociates from the methane molecule 28. As a result, a methyl radical 40 is generated on or near the catalytic surface. Two methyl radicals thus generated can couple in the gas phase to create ethane and/or ethylene, which are collectively referred to as the “C2” coupling products.

It is generally recognized that the catalytic properties of a catalyst strongly correlate to its surface morphology. Typically, the surface morphology can be defined by geometric parameters such as: (1) the number of surface atoms (e.g., the surface oxygen of FIG. 1) that coordinate to the reactant; and (2) the degree of coordinative unsaturation of the surface atoms, which is the coordination number of the surface atoms with their neighboring atoms. For example, the reactivity of a surface atom decreases with decreasing coordinative unsaturation. For example, for the dense surfaces of a face-centered crystal, a surface atom with 9 surface atom neighbors will have a different reactivity than one with 8 neighbors. Additional surface characteristics that may contribute to the catalytic properties include, for example, crystal dimensions, lattice distortion, surface reconstructions, defects, grain boundaries, and the like. See, e.g., Van Santen R. A. et al New Trends in Materials Chemistry 345-363 (1997).

Catalysts in nano-size dimensions have substantially increased surface areas compared to their counterpart bulk materials. The catalytic properties are expected to be enhanced as more surface active sites are exposed to the reactants. Typically in traditional preparations, a top-down approach (e.g., milling) is adopted to reduce the size of the bulk material. However, the surface morphologies of such catalysts remain largely the same as those of the parent bulk material.

Various embodiments described herein are directed to nanowires with controllable or tunable surface morphologies. In particular, nanowires synthesized by a “bottom up” approach, by which inorganic polycrystalline nanowires are nucleated from solution phase in the presence of a template, e.g., a polymer template. By varying the synthetic conditions, nanowires having different compositions and/or different surface morphologies are generated.

In contrast to a bulk catalyst of a given elemental composition, which is likely to have a particular corresponding surface morphology, diverse nanowires with different surface morphologies can be generated despite having the same elemental composition. In this way, morphologically diverse nanowires can be created and screened according to their catalytic activity and performance parameters in any given catalytic reaction. Advantageously, the nanowires disclosed herein and methods of producing the same have general applicability to a wide variety of heterogeneous catalyses, including without limitation: oxidative coupling of methane (e.g., FIG. 1), oxidative dehydrogenation of alkanes to their corresponding alkenes, selective oxidation of alkanes to alkenes and alkynes, oxidation of carbon monoxide, dry reforming of methane, selective oxidation of aromatics, Fischer-Tropsch reaction, hydrocarbon cracking and the like.

FIG. 2 schematically shows a high throughput work flow for synthetically generating libraries of morphologically or compositionally diverse nanowires and screening for their catalytic properties. An initial phase of the work flow involves a primary screening, which is designed to broadly and efficiently screen a large and diverse set of nanowires that logically could perform the desired catalytic transformation. For example, certain doped bulk metal oxides (e.g., Li/MgO and Sr/La₂O₃) are known catalysts for the OCM reaction. Therefore, nanowires of various metal oxide compositions and/or surface morphologies can be prepared and evaluated for their catalytic performances in an OCM reaction.

More specifically, the work flow 100 begins with designing synthetic experiments based on solution phase template formations (block 110). The synthesis, subsequent treatments and screenings can be manual or automated. As will be discussed in more detail herein, by varying the synthetic conditions, nanowires can be prepared with various surface morphologies and/or compositions in respective microwells (block 114). The nanowires are subsequently calcined and then optionally doped (block 120). Optionally, the doped and calcined nanowires are further mixed with a catalyst support (block 122). Beyond the optional support step, all subsequent steps are carried out in a “wafer” format, in which nanowire catalysts are deposited in a quartz wafer that has been etched to create an ordered array of microwells. Each microwell is a self-contained reactor, in which independently variable processing conditions can be designed to include, without limitation, respective choices of elemental compositions, catalyst support, reaction precursors, templates, reaction durations, pH values, temperatures, ratio between reactants, gas flows, and calcining conditions (block 124). Due to design constraints of some wafers, in some embodiments calcining and other temperature variables are identical in all microwells. A wafer map 130 can be created to correlate the processing conditions to the nanowire in each microwell. A library of diverse nanowires can be generated in which each library member corresponds to a particular set of processing conditions and corresponding compositional and/or morphological characteristics.

Nanowires obtained under various synthetic conditions are thereafter deposited in respective microwells of a wafer (140) for evaluating their respective catalytic properties in a given reaction (blocks 132 and 134). The catalytic performance of each library member can be screened serially by several known primary screening technologies, including scanning mass spectroscopy (SMS) (Symyx Technologies Inc., Santa Clara, Calif.). The screening process is fully automated, and the SMS tool can determine if a nanowire is catalytically active or not, as well as its relative strength as a catalyst at a particular temperature. Typically, the wafer is placed on a motion control stage capable of positioning a single well below a probe that flows the feed of the starting material over the nanowire surface and removes reaction products to a mass spectrometer and/or other detector technologies (blocks 134 and 140). The individual nanowire is heated to a preset reaction temperature, e.g., using a CO₂ IR laser from the backside of the quartz wafer and an IR camera to monitor temperature and a preset mixture of reactant gases. The SMS tool collects data with regard to the consumption of the reactant(s) and the generation of the product(s) of the catalytic reaction in each well (block 144), and at each temperature and flow rate.

The SMS data obtained as described above provide information on relative catalytic properties among all the library members (block 150). In order to obtain more quantitative data on the catalytic properties of the nanowires, possible hits that meet certain criteria are subjected to a secondary screening (block 154). Typically, secondary screening technologies include a single, or alternatively multiple channel fixed-bed or fluidized bed reactors (as described in more detail herein). In parallel reactor systems or multi-channel fixed-bed reactor system, a single feed system supplies reactants to a set of flow restrictors. The flow restrictors divide the flows evenly among parallel reactors. Care is taken to achieve uniform reaction temperature between the reactors such that the various nanowires can be differentiated solely based on their catalytic performances. The secondary screening allows for accurate determination of catalytic properties such as selectivity, yield and conversion. (block 160). These results serve as a feedback for designing further nanowire libraries. Additional description of SMS tools in a combinatorial approach for discovering catalysts can be found in, e.g., Bergh, S. et al. Topics in Catalysts 23:1-4, 2003.

Thus, in accordance with various embodiments described herein, compositional and morphologically diverse nanowires can be rationally synthesized to meet catalytic performance criteria. These and other aspects of the present disclosure are described in more detail below.

Definitions

As used herein, and unless the context dictates otherwise, the following terms have the meanings as specified below.

“Catalyst” means a substance that alters the rate of a chemical reaction. A catalyst may either increase the chemical reaction rate (i.e. a “positive catalyst”) or decrease the reaction rate (i.e. a “negative catalyst”). Catalysts participate in a reaction in a cyclic fashion such that the catalyst is cyclically regenerated. “Catalytic” means having the properties of a catalyst.

“Polymer” refers to a molecule comprised of two or more repeating structural units (i.e., “monomers”). The structural units are typically connected by covalent bonds. The structural units are, at each occurrence, independently the same or different and can be connected in any order (e.g., random, repeating, block copolymer, etc.). An exemplary polymer is polyethylene, which can be prepared using a process employing the disclosed nanowires. Certain embodiments of the polymers described herein are suitable for use as a template for forming the disclosed nanowires. Polymers in this respect include, but are not limited to, PVP (polyvinlpyrrolidone), PVA (polyvinylalcohol), PEI (polyethyleneimine), PEG (polyethyleneglycol), polyethers, polyesters, polyamides, dextran, sugar polymers, functionalized hydrocarbon polymers, functionalized polystyrene, polylactic acid, polycaprolactone, polyglycolic acid, poly(ethylene glycol)-poly(propylene glycol)-poly(ethylene glycol), copolymers and combinations of the foregoing and the like.

“Functionalized” when used in reference to a polymer means the polymer may be substituted with one or more functional groups. In general, the functional groups are moieties capable of interaction with metal ions (e.g., via coordination or other interaction) and are useful for initiating nucleation of the nanowires. Representative functional groups include, but are not limited to, amine, carboxylic acid, sulfate, alcohol, halogen (e.g., F, Cl, Br or I) and/or thiol moieties. Unless specifically stated otherwise, the polymers described herein are optionally functionalized (i.e., may either be unfunctionalized or functionalized with one or more functional groups).

“Nanoparticle” means a particle having at least one diameter on the order of nanometers (e.g. between about 1 and 100 nanometers).

“Nanowire” means a nanowire structure having at least one diameter on the order of nanometers (e.g. between about 1 and 100 nanometers) and an aspect ratio greater than 10:1. The “aspect ratio” of a nanowire is the ratio of the actual length (L) of the nanowire to the diameter (D) of the nanowire. Aspect ratio is expressed as L:D.

“Polycrystalline nanowire” means a nanowire having multiple crystal domains. Polycrystalline nanowires generally have different morphologies (e.g. bent vs. straight) as compared to the corresponding “single-crystalline” nanowires.

“Effective length” of a nanowire means the shortest distance between the two distal ends of a nanowire as measured by transmission electron microscopy (TEM) in bright field mode at 5 keV. “Average effective length” refers to the average of the effective lengths of individual nanowires within a plurality of nanowires.

“Actual length” of a nanowire means the distance between the two distal ends of a nanowire as traced through the backbone of the nanowire as measured by TEM in bright field mode at 5 keV. “Average actual length” refers to the average of the actual lengths of individual nanowires within a plurality of nanowires.

The “diameter” of a nanowire is measured in an axis perpendicular to the axis of the nanowire's actual length (i.e. perpendicular to the nanowires backbone). The diameter of a nanowire will vary from narrow to wide as measured at different points along the nanowire backbone. As used herein, the diameter of a nanowire is the most prevalent (i.e. the mode) diameter.

The “ratio of effective length to actual length” is determined by dividing the effective length by the actual length. A nanowire having a “bent morphology” will have a ratio of effective length to actual length of less than one as described in more detail herein. A straight nanowire will have a ratio of effective length to actual length equal to one as described in more detail herein.

“Inorganic” means a substance comprising a metal element. Typically, an inorganic can be one or more metals in its elemental state, or more preferably, a compound formed by a metal ion (M^(n+), wherein n 1, 2, 3, 4, 5, 6 or 7) and an anion (X^(m−), m is 1, 2, 3 or 4), which balance and neutralize the positive charges of the metal ion through electrostatic interactions. Non-limiting examples of inorganic compounds include oxides, hydroxides, halides, nitrates, sulfates, carbonates, phosphates, acetates, oxalates, and combinations thereof, of metal elements. Other non-limiting examples of inorganic compounds include Li₂CO₃, Li₂PO₄, LiOH, Li₂O, LiCl, LiBr, LiI, Li₂C₂O₄, Li₂SO₄, Na₂CO₃, Na₂PO₄, NaOH, Na₂O, NaCl, NaBr, NaI, Na₂C₂O₄, Na₂SO₄, K₂CO₃, K₂PO₄, KOH, K₂O, KCl, KBr, KI, K₂C₂O₄, K₂SO₄, Cs₂CO₃, CsPO₄, CsOH, Cs₂O, CsCl, CsBr, CsI, CsC₂O₄, CsSO₄, Be(OH)₂, BeCO₃, BePO₄, BeO, BeCl₂, BeBr₂, BeI₂, BeC₂O₄, BeSO₄, Mg(OH)₂, MgCO₃, MgPO₄, MgO, MgCl₂, MgBr₂, MgI₂, MgC₂O₄, MgSO₄, Ca(OH)₂, CaO, CaCO₃, CaPO₄, CaCl₂, CaBr₂, CaI₂, Ca(OH)₂, CaC₂O₄, CaSO₄, Y₂O₃, Y₂(CO₃)₃, Y₂(PO₄)₃, Y(OH)₃, YCl₃, YBr₃, YI₃, Y₂(C₂O₄)₃, Y₂(SO₄)₃, Zr(OH)₄, Zr(CO₃)₂, Zr(PO₄)₂, ZrO(OH)₂, ZrO₂, ZrCl₄, ZrBr₄, ZrI₄, Zr(C₂O₄)₂, Zr(SO₄)₂, Ti(OH)₄, TiO(OH)₂, Ti(CO₃)₂, Ti(PO₄)₂, TiO₂, TiCl₄, TiBr₄, TiI₄, Ti(C₂O₄)₂, Ti(SO₄)₂, BaO, Ba(OH)₂, BaCO₃, BaPO₄, BaCl₂, BaBr₂, BaI₂, BaC₂O₄, BaSO₄, La(OH)₃, La₂(CO₃)₃, La₂(PO₄)₃, La₂O₃, LaCl₃, LaBr₃, LaI₃, La₂(C₂O₄)₃, La₂(SO₄)₃, Ce(OH)₄, Ce(CO₃)₂, Ce(PO₄)₂, CeO₂, Ce₂O₃, CeCl₄, CeBr₄, CeI₄, Ce(C₂O₄)₂, Ce(SO₄)₂, ThO₂, Th(CO₃)₂, Th(PO₄)₂, ThCl₄, ThBr₄, ThI₄, Th(OH)₄, Th(C₂O₄)₂, Th(SO₄)₂, Sr(OH)₂, SrCO₃, SrPO₄, SrO, SrCl₂, SrBr₂, Srl₂, SrC₂O₄, SrSO₄, Sm₂O₃, Sm₂(CO₃)₃, Sm₂(PO₄)₃, SmCl₃, SmBr₃, SmI₃, Sm(OH)₃, Sm₂(CO₃)₃, Sm₂(C₂O₃)₃, Sm₂(SO₄)₃, LiCa₂Bi₃O₄Cl₆, Na₂WO₄, K/SrCoO₃, K/Na/SrCoO₃, Li/SrCoO₃, SrCoO₃, molybdenum oxides, molybdenum hydroxides, molybdenum carbonates, molybdenum phosphates, molybdenum chlorides, molybdenum bromides, molybdenum iodides, molybdenum oxalates, molybdenum sulfates, manganese oxides, manganese chlorides, manganese bromides, manganese iodides, manganese hydroxides, manganese oxalates, manganese sulfates, manganese tungstates, vanadium oxides, vanadium carbonates, vanadium phosphates, vanadium chlorides, vanadium bromides, vanadium iodides, vanadium hydroxides, vanadium oxalates, vanadium sulfates, tungsten oxides, tungsten carbonates, tungsten phosphates, tungsten chlorides, tungsten bromides, tungsten iodides, tungsten hydroxides, tungsten oxalates, tungsten sulfates, neodymium oxides, neodymium carbonates, neodymium phosphates, neodymium chlorides, neodymium bromides, neodymium iodides, neodymium hydroxides, neodymium oxalates, neodymium sulfates, europium oxides, europium carbonates, europium phosphates, europium chlorides, europium bromides, europium iodides, europium hydroxides, europium oxalates, europium sulfates rhenium oxides, rhenium carbonates, rhenium phosphates, rhenium chlorides, rhenium bromides, rhenium iodides, rhenium hydroxides, rhenium oxalates, rhenium sulfates, chromium oxides, chromium carbonates, chromium phosphates, chromium chlorides, chromium bromides, chromium iodides, chromium hydroxides, chromium oxalates, chromium sulfates, potassium molybdenum oxides and the like.

“Salt” means a compound comprising negative and positive ions. Salts are generally comprised of cations and counter ions. Under appropriate conditions, e.g., the solution also comprises a template, the metal ion (M^(n+)) and the anion (X^(m−)) bind to the template to induce nucleation and growth of a nanowire of M_(m)X_(n) on the template. “Anion precursor” thus is a compound that comprises an anion and a cationic counter ion, which allows the anion (X^(m−)) dissociate from the cationic counter ion in a solution. Specific examples of the metal salt and anion precursors are described in further detail herein.

“Oxide” refers to a metal compound comprising oxygen. Examples of oxides include, but are not limited to, metal oxides (M_(x)O_(y)), metal oxyhalides (M_(x)O_(y)X_(z)), metal oxynitrates (M_(x)O_(y)(NO₃)_(z)), metal phosphates (M_(x)(PO₄)_(y)), metal oxycarbonates (M_(x)O_(y)(CO₃)_(z)), metal carbonates, metal oxyhydroxides (M_(x)O_(y)(OH)_(z)) and the like, wherein x, y and z are numbers from 1 to 100.

“Crystal domain” means a continuous region over which a substance is crystalline.

“Single-crystalline nanowires” means a nanowire having a single crystal domain.

“Template” is any synthetic and/or natural material that provides at least one nucleation site where ions can nucleate and grow to form nanoparticles. In certain embodiments, the templates comprise polymers. Typically, the polymer comprises multiple binding sites that recognize certain ions and allow for the nucleation and growth of the same. Non-limiting examples of templates include the polymers described herein.

“Nucleation” refers to the process of forming a solid from solubilized particles, for example forming a nanowire in situ by converting a soluble precursor (e.g. metal and hydroxide ions) into nanocrystals in the presence of a template.

“Nucleation site” refers to a site on a template, for example a polymer, where nucleation of ions may occur. Nucleation sites include, for example, amino acids having carboxylic acid (—COOH), amino (—NH₃ ⁺ or —NH₂), hydroxyl (—OH), and/or thiol (—SH) functional groups.

“Anisotropic” means having an aspect ratio greater than one.

“Turnover number” is a measure of the number of reactant molecules a catalyst can convert to product molecules per unit time.

“Dopant” or “doping agent” is an impurity added to or incorporated within a catalyst to optimize catalytic performance (e.g. increase or decrease catalytic activity). As compared to the undoped catalyst, a doped catalyst may increase or decrease the selectivity, conversion, and/or yield of a reaction catalyzed by the catalyst.

“Atomic percent” (at % or at/at) or “atomic ratio” when used in the context of nanowire dopants refers to the ratio of the total number of dopant atoms to the total number of metal atoms in the nanowire. For example, the atomic percent of dopant in a lithium doped Mg₆MnO₈ nanowire is determined by calculating the total number of lithium atoms and dividing by the sum of the total number of magnesium and manganese atoms and multiplying by 100 (i.e., atomic percent of dopant=[Li atoms/(Mg atoms+Mn atoms)]×100).

“Weight percent” (wt/wt)” when used in the context of nanowire dopants refers to the ratio of the total weight of dopant to the total combined weight of the dopant and the nanowire. For example, the weight percent of dopant in a lithium doped Mg₆MnO₈ nanowire is determined by calculating the total weight of lithium and dividing by the sum of the total combined weight of lithium and Mg₆MnO₈ and multiplying by 100 (i.e., weight percent of dopant=[Li weight/(Li weight+Mg₆MnO₈ weight)]×100).

“Group 1” elements include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr).

“Group 2” elements include beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).

“Group 3” elements include scandium (Sc) and yttrium (Y).

“Group 4” elements include titanium (Ti), zirconium (Zr), halfnium (Hf), and rutherfordium (Rf).

“Group 5” elements include vanadium (V), niobium (Nb), tantalum (Ta), and dubnium (Db).

“Group 6” elements include chromium (Cr), molybdenum (Mo), tungsten (W), and seaborgium (Sg).

“Group 7” elements include manganese (Mn), technetium (Tc), rhenium (Re), and bohrium (Bh).

“Group 8” elements include iron (Fe), ruthenium (Ru), osmium (Os), and hassium (Hs).

“Group 9” elements include cobalt (Co), rhodium (Rh), iridium (Ir), and meitnerium (Mt).

“Group 10” elements include nickel (Ni), palladium (Pd), platinum (Pt) and darmistadium (Ds).

“Group 11” elements include copper (Cu), silver (Ag), gold (Au), and roentgenium (Rg).

“Group 12” elements include zinc (Zn), cadmium (Cd), mercury (Hg), and copernicium (Cn).

“Lanthanides” include lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), yitterbium (Yb), and lutetium (Lu).

“Actinides” include actinium (Ac), thorium (Th), protactinium (Pa), uranium (U), neptunium (Np), plutonium (Pu), americium (Am), curium (Cm), berklelium (Bk), californium (Cf), einsteinium (Es), fermium (Fm), mendelevium (Md), nobelium (No), and lawrencium (Lr).

“Metal element” or “metal” is any element, except hydrogen, selected from Groups 1 through 12, lanthanides, actinides, aluminum (Al), gallium (Ga), indium (In), tin (Sn), thallium (Tl), lead (Pb), and bismuth (Bi). Metal elements include metal elements in their elemental form as well as metal elements in an oxidized or reduced state, for example, when a metal element is combined with other elements in the form of compounds comprising metal elements. For example, metal elements can be in the form of hydrates, salts, oxides, as well as various polymorphs thereof, and the like.

“Semi-metal element” refers to an element selected from boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te), and polonium (Po).

“Non-metal element” refers to an element selected from carbon (C), nitrogen (N), oxygen (O), fluorine (F), phosphorus (P), sulfur (S), chlorine (Cl), selenium (Se), bromine (Br), iodine (I), and astatine (At).

“C2” refers to a hydrocarbon (i.e., compound consisting of carbon and hydrogen atoms) having only two carbon atoms, for example ethane and ethylene. Similarly, “C3” refers to a hydrocarbon having only 3 carbon atoms, for example propane and propylene.

“Conversion” means the mole fraction (i.e., percent) of a reactant converted to a product or products.

“Selectivity” refers to the percent of converted reactant that went to a specified product, e.g., C2 selectivity is the % of converted methane that formed ethane and ethylene, C3 selectivity is the % of converted methane that formed propane and propylene, CO selectivity is the % of converted methane that formed CO.

“Yield” is a measure of (e.g. percent) of product obtained relative to the theoretical maximum product obtainable. Yield is calculated by dividing the amount of the obtained product in moles by the theoretical yield in moles. Percent yield is calculated by multiplying this value by 100. C2 yield is defined as the sum of the ethane and ethylene molar flow at the reactor outlet multiplied by two and divided by the inlet methane molar flow. C3 yield is defined as the sum of propane and propylene molar flow at the reactor outlet multiplied by three and divided by the inlet methane molar flow. C2+ yield is the sum of the C2 yield and C3 yield. Yield is also calculable by multiplying the methane conversion by the relevant selectivity, e.g. C2 yield is equal to the methane conversion times the C2 selectivity.

“Bulk catalyst” or “bulk material” means a catalyst prepared by traditional techniques, for example by milling or grinding large catalyst particles to obtain smaller/higher surface area catalyst particles. Bulk materials are prepared with minimal control over the size and/or morphology of the material.

“Alkane” means a straight chain or branched, noncyclic or cyclic, saturated aliphatic hydrocarbon. Alkanes include linear, branched and cyclic structures. Representative straight chain alkanes include methane, ethane, n-propane, n-butane, n-pentane, n-hexane, and the like; while branched alkanes include isopropane, sec-butane, isobutanol, tert-butane, isopentane, and the like. Representative cyclic alkanes include cyclopropane, cyclobutane, cyclopentane, cyclohexane, and the like. “Alkene” means a straight chain or branched, noncyclic or cyclic, unsaturated aliphatic hydrocarbon having at least one carbon-carbon double bond. Alkenes include linear, branched and cyclic structures. Representative straight chain and branched alkenes include ethylene, propylene, 1-butene, 2-butene, isobutylene, 1-pentene, 2-pentene, 3-methyl-1-butene, 2-methyl-2-butene, 2,3-dimethyl-2-butene, and the like. Cyclic alkenes include cyclohexene and cyclopentene and the like.

“Alkyne” means a straight chain or branched, noncyclic or cyclic, unsaturated aliphatic hydrocarbon having at least one carbon-carbon triple bond. Alkynes include linear, branched and cyclic structures. Representative straight chain and branched alkynes include acetylene, propyne, 1-butyne, 2-butyne, 1-pentyne, 2-pentyne, 3-methyl-1-butyne, and the like. Representative cyclic alkynes include cycloheptyne and the like.

“Alkyl,” “alkenyl” and “alkynyl” refers to an alkane, alkene or alkyne radical, respectively.

“Aromatic” means a carbocyclic moiety having a cyclic system of conjugated p orbitals forming a delocalized conjugated r system and a number of r electrons equal to 4n+2 with n=0, 1, 2, 3, etc. Representative examples of aromatics include benzene and naphthalene and toluene. “Aryl” refers to an aromatic radical. Exemplary aryl groups include, but are not limited to, phenyl, napthyl and the like.

“Carbon-containing compounds” are compounds that comprise carbon. Non-limiting examples of carbon-containing compounds include hydrocarbons, CO and CO₂.

1. Structure/Physical Characteristics

As noted above, disclosed herein are nanowires useful as catalysts. Catalytic nanowires, and methods for preparing the same, are also described in PCT Pub. No. 2011/149996 and U.S. application Ser. No. ______, filed on Nov. 29, 2012, and entitled “Nanowire Catalysts and Methods For Their Use and Preparation,” the full disclosures of which are incorporated herein by reference in their entireties. FIG. 3 is a schematic representation of a representative nanowire 200. Typically, the nanowire is not uniform in its thickness or diameter. At any given location along the nanowire backbone, a diameter (240 a, 240 b, 240 c, 240 d) is the longest dimension of a cross section of the nanowire, i.e., is perpendicular to the axis of the nanowire backbone). FIG. 4 is a schematic representation of the nanowire 250, which shows non-uniform diameters (280 a, 280 b, 280 c and 280 d).

As noted above, in some embodiments nanowires having a “bent” morphology (i.e. “bent nanowires”) are provided. A “bent’ morphology means that the bent nanowires comprise various twists, bends and/or kinks in their general morphology as illustrated generally in FIG. 3 and discussed above. Bent nanowires have a ratio of effective length to actual length of less than one. Accordingly, in some embodiments the present disclosure provides nanowires having a ratio of effective length to actual length of less than one. In other embodiments, the nanowires have a ratio of effective length to actual length of between 0.99 and 0.01, between 0.9 and 0.1, between 0.8 and 0.2, between 0.7 and 0.3, or between 0.6 and 0.4. In other embodiments, the ratio of effective length to actual length is less than 0.99, less than 0.9, less than 0.8, less than 0.7, less than 0.6, less than 0.5, less than 0.4, less than 0.3, less than 0.2 or less than 0.1. In other embodiments, the ratio of effective length to actual length is less than 1.0 and more than 0.9, less than 1.0 and more than 0.8, less than 1.0 and more than 0.7, less than 1.0 and more than 0.6, less than 1.0 and more than 0.5, less than 1.0 and more than 0.4, less than 1.0 and more than 0.3, less than 1.0 and more than 0.2, or less than 1.0 and more than 0.1.

The ratio of effective length to actual length of a nanowire having a bent morphology may vary depending on the angle of observation. For example, one-skilled in the art will recognize that the same nanowire, when observed from different perspectives, can have a different effective length as determined by TEM. In addition, not all nanowires having a bent morphology will have the same ratio of effective length to actual length. Accordingly, in a population (i.e. plurality) of nanowires having a bent morphology, a range of ratios of effective length to actual length is expected. Although the ratio of effective length to actual length may vary from nanowire to nanowire, nanowires having a bent morphology will always have a ratio of effective length to actual length of less than one from any angle of observation.

In various embodiments, a substantially straight nanowire is provided. A substantially straight nanowire has a ratio of effective length to actual length equal to one. Accordingly, in some embodiments, the nanowires of the present disclosure have a ratio of effective length to actual length equal to one.

The actual lengths of the nanowires disclosed herein may vary. For example in some embodiments, the nanowires have an actual length of between 100 nm and 100 μm. In other embodiments, the nanowires have an actual length of between 100 nm and 10 μm. In other embodiments, the nanowires have an actual length of between 200 nm and 10 μm. In other embodiments, the nanowires have an actual length of between 500 nm and 5 μm. In other embodiments, the actual length is greater than 5 μm. In other embodiments, the nanowires have an actual length of between 800 nm and 1000 nm. In other further embodiments, the nanowires have an actual length of 900 nm. As noted below, the actual length of the nanowires may be determined by TEM, for example, in bright field mode at 5 keV.

The diameter of the nanowires may be different at different points along the nanowire backbone. However, the nanowires comprise a mode diameter (i.e. the most frequently occurring diameter). As used herein, the diameter of a nanowire refers to the mode diameter. In some embodiments, the nanowires have a diameter of between 1 nm and 10 μm, between 1 nm and 1 μm, between 1 nm and 500 nm, between 1 nm and 100 nm, between 7 nm and 100 nm, between 7 nm and 50 nm, between 7 nm and 25 nm, or between 7 nm and 15 nm. On other embodiments, the diameter is greater than 500 nm. As noted below, the diameter of the nanowires may be determined by TEM, for example, in bright field mode at 5 keV.

Various embodiments of the present disclosure provide nanowires having different aspect ratios. In some embodiments, the nanowires have an aspect ratio of greater than 10:1. In other embodiments, the nanowires have an aspect ratio greater than 20:1. In other embodiments, the nanowires have an aspect ratio greater than 50:1. In other embodiments, the nanowires have an aspect ratio greater than 100:1.

In some embodiments, the nanowires comprise a solid core while in other embodiments, the nanowires comprise a hollow core.

The morphology of a nanowire (including length, diameter, and other parameters) can be determined by transmission electron microscopy (TEM). Transmission electron microscopy (TEM) is a technique whereby a beam of electrons is transmitted through an ultra thin specimen, interacting with the specimen as it passes through. An image is formed from the interaction of the electrons transmitted through the specimen. The image is magnified and focused onto an imaging device, such as a fluorescent screen, on a layer of photographic film or detected by a sensor such as a CCD camera. TEM techniques are well known to those of skill in the art.

A TEM image of nanowires may be taken, for example, in bright field mode at 5 keV.

The nanowires of the present disclosure can be further characterized by powder x-ray diffraction (XRD). XRD is a technique capable of revealing information about the crystallographic structure, chemical composition, and physical properties of materials, including nanowires. XRD is based on observing the diffracted intensity of an X-ray beam hitting a sample as a function of incident and diffraction angle, polarization, and wavelength or energy.

Crystal structure, composition, and phase, including the crystal domain size of the nanowires, can be determined by XRD. In some embodiments, the nanowires comprise a single crystal domain (i.e. single crystalline). In other embodiments, the nanowires comprise multiple crystal domains (i.e. polycrystalline). In some other embodiments, the average crystal domain of the nanowires is less than 100 nm, less than 50 nm, less than 30 nm, less than 20 nm, less than 10 nm, less than 5 nm, or less than 2 nm.

Typically, a catalytic material described herein comprises a plurality of nanowires. In certain embodiments, the plurality of nanowires form a mesh of randomly distributed and, to various degrees, interconnected nanowires. FIG. 5 is a schematic representation of a nanowire mesh 300.

The total surface area per gram of a nanowire or plurality of nanowires may have an effect on the catalytic performance. Pore size distribution may affect the nanowires catalytic performance as well. Surface area and pore size distribution of the nanowires or plurality of nanowires can be determined by BET (Brunauer, Emmett, Teller) measurements. BET techniques utilize nitrogen adsorption at various temperatures and partial pressures to determine the surface area and pore sizes of catalysts. BET techniques for determining surface area and pore size distribution are well known in the art.

In some embodiments the nanowires have a surface area of between 0.0001 and 3000 m²/g, between 0.0001 and 2000 m²/g, between 0.0001 and 1000 m²/g, between 0.0001 and 500 m²/g, between 0.0001 and 100 m²/g, between 0.0001 and 50 m²/g, between 0.0001 and 20 m²/g, between 0.0001 and 10 m²/g or between 0.0001 and 5 m²/g.

In some embodiments the nanowires have a surface area of between 0.001 and 3000 m²/g, between 0.001 and 2000 m²/g, between 0.001 and 1000 m²/g, between 0.001 and 500 m²/g, between 0.001 and 100 m²/g, between 0.001 and 50 m²/g, between 0.001 and 20 m²/g, between 0.001 and 10 m²/g or between 0.001 and 5 m²/g.

In some other embodiments the nanowires have a surface area of between 2000 and 3000 m²/g, between 1000 and 2000 m²/g, between 500 and 1000 m²/g, between 100 and 500 m²/g, between 10 and 100 m²/g, between 5 and 50 m²/g, between 2 and 20 m²/g or between 0.0001 and 10 m²/g.

In other embodiments, the nanowires have a surface area of greater than 2000 m²/g, greater than 1000 m²/g, greater than 500 m²/g, greater than 100 m²/g, greater than 50 m²/g, greater than 20 m²/g, greater than 10 m²/g, greater than 5 m²/g, greater than 1 m²/g, greater than 0.0001 m²/g.

2. Chemical Composition

As noted above, disclosed herein are nanowires useful as catalysts. The catalytic nanowires may have any number of compositions and morphologies. In some embodiments, the nanowires are inorganic. In other embodiments, the nanowires are polycrystalline. In some other embodiments, the nanowires are inorganic and polycrystalline. In yet other embodiments, the nanowires are single-crystalline, or in other embodiments the nanowires are inorganic and single-crystalline. In still other embodiments of any of the foregoing, the nanowires may have a ratio of effective length to actual length of less than one and an aspect ratio of greater than ten as measured by TEM in bright field mode at 5 keV. In still other embodiments of any of the forgoing, the nanowires may comprise one or more elements from any of Groups 1 through 7, lanthanides, actinides or combinations thereof.

In some embodiments, the nanowires comprise one or more metal elements from any of Groups 1-7, lanthanides, actinides or combinations thereof, for example, the nanowires may be mono-metallic, bi-metallic, tri-metallic, etc (i.e. contain one, two, three, etc. metal elements). In some embodiments, the metal elements are present in the nanowires in elemental form while in other embodiments the metal elements are present in the nanowires in oxidized form. In other embodiments the metal elements are present in the nanowires in the form of a compound comprising a metal element. The metal element or compound comprising the metal element may be in the form of oxides, hydroxides, oxyhydroxides, salts, hydrated oxides, carbonates, oxy-carbonates, sulfates, phosphates, acetates, oxalates and the like. The metal element or compound comprising the metal element may also be in the form of any of a number of different polymorphs or crystal structures.

In certain examples, metal oxides may be hygroscopic and may change forms once exposed to air, may absorb carbon dioxide, may be subjected to incomplete calcination or any combination thereof. Accordingly, although the nanowires are often referred to as metal oxides, in certain embodiments the nanowires also comprise hydrated oxides, oxyhydroxides, hydroxides, oxycarbonates (or oxide carbonates), carbonates or combinations thereof.

In other embodiments, the nanowires comprise one or more metal elements from Group 1. In other embodiments, the nanowires comprise one or more metal elements from Group 2. In other embodiments, the nanowires comprise one or more metal elements from Group 3. In other embodiments, the nanowires comprise one or more metal elements from Group 4. In other embodiments, the nanowires comprise one or more metal elements from Group 5. In other embodiments, the nanowires comprise one or more metal elements from Group 6. In other embodiments, the nanowires comprise one or more metal elements from Group 7. In other embodiments, the nanowires comprise one or more metal elements from the lanthanides. In other embodiments, the nanowires comprise one or more metal elements from the actinides.

In one embodiment, the nanowires comprise one or more metal elements from any of Groups 1-7, lanthanides, actinides or combinations thereof in the form of an oxide. In another embodiment, the nanowires comprise one or more metal elements from Group 1 in the form of an oxide. In another embodiment, the nanowires comprise one or more metal elements from Group 2 in the form of an oxide. In another embodiment, the nanowires comprise one or more metal elements from Group 3 in the form of an oxide. In another embodiment, the nanowires comprise one or more metal elements from Group 4 in the form of an oxide. In another embodiment, the nanowires comprise one or more metal elements from Group 5 in the form of an oxide. In another embodiment, the nanowires comprise one or more metal elements from Group 6 in the form of an oxide. In another embodiment, the nanowires comprise one or more metal elements from Group 7 in the form of an oxide. In another embodiment, the nanowires comprise one or more metal elements from the lanthanides in the form of an oxide. In another embodiment, the nanowires comprise one or more metal elements from the actinides in the form of an oxide.

In other embodiments, the nanowires comprise oxides, hydroxides, sulfates, carbonates, oxide carbonates, acetates, oxalates, phosphates (including hydrogenphosphates and dihydrogenphosphates), oxyhalides, hydroxyhalides, oxyhydroxides, oxysulfates or combinations thereof of one or more metal elements from any of Groups 1-7, lanthanides, actinides or combinations thereof. In some other embodiments, the nanowires comprise oxides, hydroxides, sulfates, carbonates, oxide carbonates, oxalates or combinations thereof of one or more metal elements from any of Groups 1-7, lanthanides, actinides or combinations thereof. In other embodiments, the nanowires comprise oxides, and in other embodiments, the nanowires comprise hydroxides. In other embodiments, the nanowires comprise carbonates, and in other embodiments, the nanowires comprise oxy-carbonates. In other embodiments, the nanowires comprise Li₂CO₃, LiOH, Li₂O, Li₂C₂O₄, Li₂SO₄, Na₂CO₃, NaOH, Na₂O, Na₂C₂O₄, Na₂SO₄, K₂C₀₀₃, KOH, K₂O, K₂C₂O₄, K₂SO₄, Cs₂CO₃, CsOH, Cs₂O, CsC₂O₄, CsSO₄, Be(OH)₂, BeCO₃, BeO, BeC₂O₄, BeSO₄, Mg(OH)₂, MgCO₃, MgO, MgC₂O₄. MgSO₄, Ca(OH)₂, CaO, CaCO₃, CaC₂O₄, CaSO₄, Y₂O₃, Y₃(CO₃)₂, Y(OH)₃, Y₂(C₂O₄)₃, Y₂(SO₄)₃, Zr(OH)₄, ZrO(OH)₂, ZrO₂, Zr(C₂O₄)₂, Zr(SO₄)₂, Ti(OH)₄, TiO(OH)₂, TiO₂, Ti(C₂O₄)₂, Ti(SO₄)₂, BaO, Ba(OH)₂, BaCO₃, BaC₂O₄, BaSO₄, La(OH)₃, La₂O₃, La₂(C₂O₄)₃, La₂(SO₄)₃, La₂(CO₃)₃, Ce(OH)₄, CeO₂, Ce₂O₃, Ce(C₂O₄)₂, Ce(SO₄)₂, Ce(CO₃)₂, ThO₂, Th(OH)₄, Th(C₂O₄)₂, Th(SO₄)₂, Th(CO₃)₂, Sr(OH)₂, SrCO₃, SrO, SrC₂O₄, SrSO₄, Sm₂O₃, Sm(OH)₃, Sm₂(CO₃)₃, Sm₂(C₂O₃)₃, Sm₂(SO₄)₃, LiCa₂Bi₃O₄Cl₆, NaMnO₄, Na₂WO₄, NaMn/WO₄, CoWO₄, CuWO₄, K/SrCoO₃, K/Na/SrCoO₃, Na/SrCoO₃, Li/SrCoO₃, SrCoO₃, Mg₆MnO₈, LiMn₂O₄, Li/Mg₆MnO₈, Na₁₀Mn/W₅O₁₇, Mg₃Mn₃B₂O₁₀, Mg₃(BO₃)₂, molybdenum oxides, molybdenum hydroxides, molybdenum oxalates, molybdenum sulfates, Mn₂O₃, Mn₃O₄, manganese oxides, manganese hydroxides, manganese oxalates, manganese sulfates, manganese tungstates, manganese carbonates, vanadium oxides, vanadium hydroxides, vanadium oxalates, vanadium sulfates, tungsten oxides, tungsten hydroxides, tungsten oxalates, tungsten sulfates, neodymium oxides, neodymium hydroxides, neodymium carbonates, neodymium oxalates, neodymium sulfates, europium oxides, europium hydroxides, europium carbonates, europium oxalates, europium sulfates, praseodymium oxides, praseodymium hydroxides, praseodymium carbonates, praseodymium oxalates, praseodymium sulfates, rhenium oxides, rhenium hydroxides, rhenium oxalates, rhenium sulfates, chromium oxides, chromium hydroxides, chromium oxalates, chromium sulfates, potassium molybdenum oxides/silicon oxide or combinations thereof.

In other embodiments, the nanowires comprise Li₂O, Na₂O, K₂O, Cs₂O, BeO MgO, CaO, ZrO(OH)₂, ZrO₂, TiO₂, TiO(OH)₂, BaO, Y₂O₃, La₂O₃, CeO₂, Ce₂O₃, ThO₂, SrO, Sm₂O₃, Nd₂O₃, Eu₂O₃, Pr₂O₃, LiCa₂Bi₃O₄Cl₆, NaMnO₄, Na₂WO₄, Na/Mn/WO₄, Na/MnWO₄, Mn/WO₄, K/SrCoO₃, K/Na/SrCoO₃, K/SrCoO₃, Na/SrCoO₃, Li/SrCoO₃, SrCoO₃, Mg₆MnO₈, Na/B/Mg₆MnO₈, Li/B/Mg₆MnO₈, Zr₂Mo₂O₈, molybdenum oxides, Mn₂O₃, Mn₃O₄, manganese oxides, vanadium oxides, tungsten oxides, neodymium oxides, rhenium oxides, chromium oxides, or combinations thereof.

In still other aspects, the nanowires comprise lanthanide containing perovskites. A perovskite is any material with the same type of crystal structure as calcium titanium oxide (CaTiO₃). Examples of perovskites within the context of the present disclosure include, but are not limited to, LaCoO₃ and La/SrCoO₃.

In other embodiments, the nanowires comprise TiO₂, Sm₂O₃, V₂O₅, MoO₃, BeO, MnO₂, MgO, La₂O₃, Nd₂O₃, Eu₂O₃, ZrO₂, SrO, Na₂WO₄, Mn/WO₄, BaO, Mn₂O₃, Mn₃O₄, Mg₆MnO₈, Na/B/Mg₆MnO₈, Li/B/Mg₆MnO₈, NaMnO₄, CaO or combinations thereof. In further embodiments, the nanowires comprise MgO, La₂O₃, Nd₂O₃, Na₂WO₄, Mn/WO₄, Mn₂O₃, Mn₃O₄, Mg₆MnO₈, Na/B/Mg₆MnO₈, Li/B/Mg₆MnO₈ or combinations thereof.

In some embodiments, the nanowires comprises Mg, Ca, Sr, Ba, Y, La, W, Mn, Mo, Nd, Sm, Eu, Pr, Zr or combinations thereof, and in other embodiments the nanowire comprises MgO, CaO, SrO, BaO, Y₂O₃, La₂O₃, Na₂WO₄, Mn₂O₃, Mn₃O₄, Nd₂O₃, Sm₂O₃, Eu₂O₃, Pr₂O₃, Mg₆MnO₈, NaMnO₄, Na/Mn/W/O, Na/MnWO₄, MnWO₄ or combinations thereof.

In more specific embodiments, the nanowires comprise MgO. In other specific embodiments, the nanowires comprise CaO. In other embodiments, the nanowires comprise SrO. In other specific embodiments, the nanowires comprise La₂O₃. In other specific embodiments, the nanowires comprise Na₂WO₄ and may optionally further comprise Mn/WO₄. In other specific embodiments, the nanowires comprise Mn₂O₃. In other specific embodiments, the nanowires comprise Mn₃O₄. In other specific embodiments, the nanowires comprise Mg₆MnO₈. In other specific embodiments, the nanowires comprise NaMnO₄. In other specific embodiments, the nanowires comprise Nd₂O₃. In other specific embodiments, the nanowires comprise Eu₂O₃. In other specific embodiments, the nanowires comprise Pr₂O₃. In some other embodiments, the nanowires comprise Sm₂O₃.

In certain embodiments, the nanowires comprise an oxide of a group 2 element. For example, in some embodiments, the nanowires comprise an oxide of magnesium. In other embodiments, the nanowires comprise an oxide of calcium. In other embodiments, the nanowires comprise an oxide of strontium. In other embodiments, the nanowires comprise an oxide of barium.

In certain other embodiments, the nanowires comprise an oxide of a group 3 element. For example, in some embodiments, the nanowires comprise an oxide of yttrium. In other embodiments, the nanowires comprise an oxide of scandium.

In yet other certain embodiments, the nanowires comprise an oxide of an early lanthanide element. For example, in some embodiments, the nanowires comprise an oxide of lanthanum. In other embodiments, the nanowires comprise an oxide of cerium. In other embodiments, the nanowires comprise an oxide of praseodymium. In other embodiments, the nanowires comprise an oxide of neodymium. In other embodiments, the nanowires comprise an oxide of promethium. In other embodiments, the nanowires comprise an oxide of samarium. In other embodiments, the nanowires comprise an oxide of europium. In other embodiments, the nanowires comprise an oxide of gadolinium.

In certain other embodiments, the nanowires comprise a lanthanide in the form of an oxy-carbonate. For example, the nanowires may comprise Ln₂O₂(CO₃), where Ln represents a lanthanide. Examples in this regard include: La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu oxy-carbonates. In other embodiments, the nanowires comprise an oxy-carbonate of one or more elements from any of Groups 1 through 7, lanthanides, actinides or combinations thereof. Accordingly in one embodiment the nanowires comprise Li, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Tc or Re oxy-carbonate. In other embodiments, the nanowires comprise Ac, Th, U or Pa oxide carbonate. An oxy-carbonate may be represented by the following formula: M_(x)O_(y)(CO₃)_(z), wherein M is a metal element from any of Groups 1 through 7, lanthanides or actinides and x, y and z are integers such that the overall charge of the metal oxy-carbonate is neutral.

In certain other embodiments, the nanowires comprise a carbonate of a group 2 element. For example, the nanowires may comprise MgCO₃, CaCO₃, SrCO₃, BaCO₃ or combination thereof. In other embodiments, the nanowires comprise a carbonate of one or more elements from any of the Group 1 through 7, lanthanides and actinides or combination thereof. Accordingly in one embodiment the nanowires comprise a Li, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ac, Th, Pa or U carbonate.

In other embodiments, the nanowires comprise TiO₂, Sm₂O₃, V₂O₅, MoO₃, BeO, MnO₂, MgO, La₂O₃, ZrO₂, SrO, Na₂WO₄, BaCO₃, Mn₂O₃, Mn₃O₄, Mg₆MnO₈, Na/B/Mg₆MnO₈, Li/B/Mg₆MnO₈, Zr₂Mo₂O₈, NaMnO₄, CaO or combinations thereof and further comprise one or more dopants comprised of metal elements, semi-metal elements, non-metal elements or combinations thereof. In some further embodiments, the nanowires comprise MgO, La₂O₃, Na₂WO₄, Mn₂O₃, Mn₃O₄, Mg₆MnO₈, Zr₂Mo₂O₈, NaMnO₄ or combinations thereof, and the nanowires further comprise Li, Sr, Zr, Ba, Mn or Mn/WO₄.

In some embodiments, the nanowires or a catalytic material comprising a plurality of the nanowires comprise a combination of one or more of metal elements from any of Groups 1-7, lanthanides or actinides and one or more of metal elements, semi-metal elements or non-metal elements. For example in one embodiment, the nanowires comprise the combinations of Li/Mg/O, Ba/Mg/O, Zr/La/O, Ba/La/O, Sr/La/O, Zr/V/P/O, Mo/V/Sb/O, V₂O₅/Al₂O₃, Mo/V/O, V/Ce/O, V/Ti/P/O, V₂O₅/TiO₂, V/P/O/TiO₂, V/P/O/Al₂O₃, V/Mg/O, V₂O₅/ZrO₂, Mo/V/Te/O, V/Mo/O/Al₂O₃, Ni/V/Sb/O, Co/V/Sb/O, Sn/V/Sb/O, Bi/V/Sb/O, Mo/V/Te/Nb/O, Mo/V/Nb/O, V₂O₅/MgO/SiO₂, V/Co, MoO₃/Al₂O₃, Ni/Nb/O, NiO/Al₂O₃, Ga/Cr/Zr/P/O, MoO₃/Cl/SiO₂/TiO₂, Co/Cr/Sn/W/O, Cr/Mo/O, MoO₃/Cl/SiO₂/TiO₂, Co/Ca, NiO/MgO, MoO₃/Al₂O₃, Nb/P/Mo/O, Mo/V/Te/Sb//Nb/O, La/Na/Al/O, Ni/Ta/Nb/O, Mo/Mn/V/W/O, Li/Dy/Mg/O, Sr/La/Nd/O, Co/Cr/Sn/W/O, MoO₃/SiO₂/TiO₂, Sm/Na/P/O, Sm/Sr/O, Sr/La/Nd/O, Co/P/O/TiO₂, La/Sr/Fe/Cl/O, La/Sr/Cu/Cl/O, Y/Ba/Cu/O, Na/Ca/O, V₂O₅/ZrO₂, V/Mg/O, Mn/N/Cr/W/O/Al₂O₃, V₂O₅/K/SiO₂, V₂O₅/Ca/TiO₂, V₂O₅/K/TiO₂, V/Mg/Al/O, V/Zr/O, V/Nb/O, V₂O₅/Ga₂O₃, V/Mg/Al/O, V/Nb/O, V/Sb/O, V/Mn/O, V/Nb/O/Sb₂O₄, V/Sb/O/TiO₂, V₂O₅/Ca, V₂O₅/K/Al₂O₃, V₂O₅/TiO₂, V₂O₅/MgO/TiO₂, V₂O₅/ZrO₂, V/Al/F/O, V/Nb/O/TiO₂, Ni/V/O, V₂O₅/SmVO₄, V/W/O, V₂O₅/Zn/Al₂O₃, V₂O₅/CeO₂, V/Sm/O, V₂O₅/TiO₂/SiO₂, Mo/Li/O/Al₂O₃, Mg/Dy/Li/Cl/O, Mg/Dy/Li/Cl/O, Ce/Ni/O, Ni/Mo/ON, Ni/Mo/O/V/N, Ni/Mo/O Sb/O/N, MoO₃/Cl/SiO₂/TiO₂, Co/Mo/O, Ni/Ti/O, Ni/Zr/O, Cr/O, MoO₃/Al₂O₃, Mn/P/O, MoO₃/K/ZrO₂, Na/W/O, Mn/Na/W/O, Mn/Na//W/O/SiO₂, Na/W/O/SiO₂, Mn/Mo/O, Nb₂O₅/TiO₂, Co/W/O, Ni/Mo/O, Ga/Mo/O, Mg/Mo/V/O, Cr₂O₃/Al₂O₃, Cr/Mo/Cs/O/Al₂O₃, Co/Sr/O/Ca, Ag/Mo/P/O, MoO₃/SmVO₄, Mo/Mg/Al/O, MoO₃/K/SiO₂/TiO₂, Cr/Mo/O/Al₂O₃, MoO₃/Al₂O₃, Ni/Co/Mo/O, Y/Zr/O, Y/Hf, Zr/Mo/Mn/O, Mg/Mn/O, Li/Mn/O, Mg/Mn/B/O, Mg/B/O, Na/B/Mg/Mn/O, Li/B/Mg/Mn/O, Mn/Na/P/O, Na/Mn/Mg/O, Zr/Mo/O, Mn/W/O or Mg/Mn/O.

In a specific embodiment, the nanowires comprise the combinations of Li/Mg/O, Ba/Mg/O, Zr/La/O, Ba/La/O, Sr/La/O, Sr/Nd/O, La/O, Nd/O, Eu/O, Mg/La/O, Mg/Nd/O, Na/La/O, Na/Nd/O, Sm/O, Mn/Na/W/O, Mg/Mn/O, Na/B/Mg/Mn/O, Li/B/Mg/Mn/O, Zr/Mo/O or Na/Mn/Mg/O. For example, in some embodiments the nanowires comprise the combinations of Li/MgO, Ba/MgO, Sr/La₂O₃, Ba/La₂O₃, Mn/Na₂WO₄, Mn/Na₂WO₄/SiO₂, Mn₂O₃/Na₂WO₄, Mn₃O₄/Na₂WO₄, Li/B/Mg₆MnO₈, Na/B/Mg₆MnO₈ or NaMnO₄/MgO. In certain embodiments, the nanowire comprises Li/MgO, Ba/MgO, Sr/La₂O₃, Mg/Na/La₂O₃, Sr/Nd₂O₃, or Mn/Na₂WO₄.

In some other specific embodiments, the nanowires comprise the combination of Li/MgO. In other specific embodiments, the nanowires comprise the combination of Ba/MgO. In other specific embodiments, the nanowires comprise the combination of Sr/La₂O₃. In other specific embodiments, the nanowires comprise the combination of Ba/La₂O₃. In other specific embodiments, the nanowires comprise the combination of Mn/Na₂WO₄. In other specific embodiments, the nanowires comprise the combination of Mn/Na₂WO₄/SiO₂. In other specific embodiments, the nanowires comprise the combination of Mn₂O₃/Na₂WO₄. In other specific embodiments, the nanowires comprise the combination of Mn₃O₄/Na₂WO₄. In other specific embodiments, the nanowires comprise the combination of Mn/WO₄/Na₂WO₄. In other specific embodiments, the nanowires comprise the combination of Li/B/Mg₆MnO₈. In other specific embodiments, the nanowires comprise the combination of Na/B/Mg₆MnO₈. In other specific embodiments, the nanowires comprise the combination of NaMnO₄/MgO.

Polyoxyometalates (POM) are a class of metal oxides that range in structure from the molecular to the micrometer scale. The unique physical and chemical properties of POM clusters, and the ability to tune these properties by synthetic means have attracted significant interest from the scientific community to create “designer” materials. For example, heteropolyanions such as the well-known Keggin [XM₁₂O₄₀]⁻ and Wells-Dawson [X₂M1₈O₆₂]⁻ anions (where M=W or Mo; and X=a tetrahedral template such as but not limited to Si, Ge, P) and isopolyanions with metal oxide frameworks with general formulas [MO_(x)]_(n) where M=Mo, W, V, and Nb and x=4-7 are ideal candidates for OCM/ODH catalysts. Accordingly, in one embodiment the nanowires comprise [XM₁₂O₄₀]⁻ or [X₂M1₈O₆₂]⁻ anions (where M=W or Mo; and X=a tetrahedral template such as but not limited to Si, Ge, P) and isopolyanions with metal oxide frameworks with general formulas [MO_(x)]_(n) where M=Mo, W, V, and Nb and x=4-7. In some embodiments, X is P or Si.

These POM clusters have “lacunary” sites that can accommodate divalent and trivalent first row transition metals, the metal oxide clusters acting as ligands. These lacunary sites are essentially “doping” sites, allowing the dopant to be dispersed at the molecular level instead of in the bulk which can create pockets of unevenly dispersed doped material. Because the POM clusters can be manipulated by standard synthetic techniques, POMs are highly modular and a wide library of materials can be prepared with different compositions, cluster size, and dopant oxidation state. These parameters can be tuned to yield desired OCM/ODH catalytic properties. Accordingly, one embodiment of the present disclosure is a nanowire comprising one or more POM clusters. Such nanowires find utility as catalysts, for example, in the OCM and ODH reactions.

Silica doped sodium manganese tungstate (NaMn/WO₄/SiO₂) is a promising OCM catalyst. The NaMn/WO₄/SiO₂ system is attractive due to its high C2 selectivity and yield. Unfortunately, good catalytic activity is only achievable at temperatures greater than 800° C. and although the exact active portion of the catalyst is still subject to debate, it is thought that sodium plays an important role in the catalytic cycle. In addition, the NaMn/WO₄/SiO₂ catalyst surface area is relatively low <2 m²/g. Manganese tungstate (Mn/WO₄) nanorods (i.e., straight nanowires) can be used to model a NaMn/WO₄/SiO₂ based nanowire OCM catalyst. The Mn/WO₄ nanorods are prepared hydro-thermally and the size can be tuned based on reaction conditions with dimensions of 25-75 nm in diameter to 200-800 nm in length. The as-prepared nano-rods have higher surface areas than the NaMn/WO₄/SiO₂ catalyst systems. In addition, the amount of sodium, or other elements, can be precisely doped into the Mn/WO₄ nanorod material to target optimal catalytic activity. Nanorod tungstate based materials can be expanded to, but not limited to, CoWO₄ or CuWO₄ materials, which may serve as base materials for OCM/ODH catalysis. In addition to straight nanowires, the above discussion applies to the disclosed nanowires having a bent morphology as well. The nanowires of the disclosure may be analyzed by inductively coupled plasma mass spectrometry (ICP-MS) to determine the element content of the nanowires. ICP-MS is a type of mass spectrometry that is highly sensitive and capable of the determination of a range of metals and several non-metals at concentrations below one part in 10¹². ICP is based on coupling together an inductively coupled plasma as a method of producing ions (ionization) with a mass spectrometer as a method of separating and detecting the ions. ICP-MS methods are well known in the art.

In some embodiments, the nanowire comprises a combination of two or more metal compounds, for example metal oxides. For example, in some embodiments, the nanowire comprises Mn₂O₃/Na₂WO₄, Mn₃O₄/Na₂WO₄ MnWO₄/Na₂WO₄/Mn₂O₃, MnWO₄/Na₂WO₄/Mn₃O₄ or NaMnO₄/MgO.

Certain rare earth compositions have been found to be useful catalysts, for example as catalysts in the OCM reaction. Thus, in one embodiment, the nanowire catalysts comprise lanthanide oxides such as La₂O₃, Nd₂O₃, Yb₂O₃, Eu₂O₃ or Sm₂O₃. In other embodiments, the nanowires comprise mixed oxides of lanthanide metals. Such mixed oxides are represented by Ln1_(4-x)Ln2_(x)O₆, wherein Ln1 and Ln2 are each independently a lanthanide element and x is a number ranging from greater than 0 to less than 4. In other more specific embodiments, the lanthanide mixed oxides comprise La_(4-x)Ln1_(x)O₆, wherein Ln1 is a lanthanide element and x is a number ranging from greater than 0 to less than 4. For example, in some embodiments the lanthanide mixed oxides are mixed oxides of lanthanum and neodymium and the nanowires comprise La_(4-x)Nd_(x)O₆, wherein x is a number ranging from greater than 0 to less than 4 have also been found to be useful in the OCM reaction. For example La₃NdO₆, LaNd₃O₆, La_(1.5)Nd_(2.5)O₆, La_(2.5)Nd_(1.5)O₆, La_(3.2)Nd_(0.8)O₆, La_(3.5)Nd_(0.5)O₆, La_(3.8)Nd_(0.2)O₆, or combinations thereof have been found to be useful OCM catalyst compositions.

Any of the foregoing nanowire catalysts may have any morphology (e.g., bent, straight, etc.) and may be prepared via any method described herein or known in the art. For example, these nanowires may be prepared from any of the polymer templates described herein or known in the art. Also as discussed below, certain dopant combinations with the above lanthanide nanowires have been found to be useful for enhancing the catalytic activity of the nanowires.

In other embodiments the nanowires are in a core/shell arrangement (see below) and the nanowires comprise Eu on a MgO core; La on a MgO core; Nd on a MgO core; Sm on a MgO core; Y—Ce on a Na doped MgO core Na or Na doped Ce—Y on a MgO core.

In an aspect of the invention, nanowires, and materials comprising the same, having the empirical formula M4_(w)M5_(x)M6_(y)O_(z) are provided, wherein each M4 is independently one or more elements selected from Groups 1 through 4, each M5 is independently one or more elements selected from Group 7 and M6 is independently one or more elements selected from Groups 5 through 8 and Groups 14 through 15 and w, x, y and z are integers such that the overall charge is balanced.

In some embodiments, M4 comprises one or more elements selected from Group 1, such as sodium (Na), while M6 includes one or more elements selected from Group 6, such as tungsten (W) and M5 is Mn. In another embodiment, M4 is Na, M5 is Mn, M6 is W, the ratio of w:x is 10:1, and the ratio of w:y is 2:1. In such a case, the overall empirical formula of the nanowire is Na₁₀MnW₅O_(z). When Na is in the +1 oxidation state, W is in the +6 oxidation state, and Mn is in the +4 oxidation state, z must equal 17 so as to fill the valence requirements of Na, W and Mn. As a result, the overall empirical formula of the nanowire in this embodiment is Na₁₀MnW₅O₁₇.

In other embodiments, the ratios of w:x can be 1:1, or 5:1, or 15:1, or 25:1, or 50:1. In yet other embodiments, for any given ratio of w:x, the ratios of w:y can be 1:5, or 1:2, or 1:2, or 5:1. In still other embodiments, any nanowire of the empirical formula M4_(w)M5_(x)M6_(y)O_(z), including the nanowire of the empirical formula M4₁₀MnM6₅O₁₇ described above, can be supported on an oxide substrate. Oxide substrates can include silica, alumina, and titania. The reaction that anchors nanowire materials onto oxide substrates is analogous to the reaction that anchors bulk materials onto oxide substrates, such as that described in U.S. Pat. No. 4,808,563, which is entirely incorporated herein by reference. Alternatively, non-oxide support, for example silicon carbide can be used to support nanowires of the present invention, for example Na₁₀MnW₅O₁₇ nanowires and others. Silicon carbide has very good high temperature stability and chemical inertness toward OCM reaction intermediates and thus is particularly effective as a support in this reaction.

3. Catalytic Materials

As noted above, the present disclosure provides a catalytic material comprising a plurality of nanowires. In certain embodiments, the catalytic material comprises a support or carrier. The support is preferably porous and has a high surface area. In some embodiments the support is active (i.e. has catalytic activity). In other embodiments, the support is inactive (i.e. non-catalytic). In some embodiments, the support comprises an inorganic oxide, Al₂O₃, SiO₂, TiO₂, MgO, CaO, SrO, ZrO₂, ZnO, LiAlO₂, MgAl₂O₄, MnO, MnO₂, Mn₃O₄, La₂O₃, AlPO₄, SiO₂/Al₂O₃, activated carbon, silica gel, zeolites, activated clays, activated Al₂O₃, SiC, diatomaceous earth, magnesia, aluminosilicates, calcium aluminate, support nanowires or combinations thereof. In some embodiments the support comprises silicon, for example SiO₂. In other embodiments the support comprises magnesium, for example MgO. In other embodiments the support comprises zirconium, for example ZrO₂. In yet other embodiments, the support comprises lanthanum, for example La₂O₃. In yet other embodiments, the support comprises lanthanum, for example Y₂O₃. In yet other embodiments, the support comprises hafnium, for example HfO₂. In yet other embodiments, the support comprises aluminum, for example Al₂O₃. In yet other embodiments, the support comprises gallium, for example Ga₂O₃.

In still other embodiments, the support material comprises an inorganic oxide, Al₂O₃, SiO₂, TiO₂, MgO, ZrO₂, HfO₂, CaO, SrO, ZnO, LiAlO₂, MgAl₂O₄, MnO, MnO₂, Mn₂O₄, Mn₃O₄, La₂O₃, activated carbon, silica gel, zeolites, activated clays, activated Al₂O₃, diatomaceous earth, magnesia, aluminosilicates, calcium aluminate, support nanowires or combinations thereof. For example, the support material may comprise SiO₂, ZrO₂, CaO, La₂O₃ or MgO.

In still other embodiments, the support material comprises a carbonate. For example, in some embodiments the support material comprises MgCO₃, CaCO₃, SrCO₃, BaCO₃, Y₂(CO₃)₃, La₂(CO₃)₃ or combinations thereof.

In yet other embodiments, a nanowire may serve as a support for another nanowire. For example, a nanowire may be comprised of non-catalytic metal elements and adhered to or incorporated within the support nanowire is a catalytic nanowire. For example, in some embodiments, the support nanowires are comprised of SiO₂, MgO, CaO, SrO, TiO₂, ZrO₂, Al₂O₃, ZnO MgCO₃, CaCO₃, SrCO₃ or combinations thereof. Preparation of nanowire supported nanowire catalysts (i.e., core/shell nanowires) is discussed in more detail below. The optimum amount of nanowire present on the support depends, inter alia, on the catalytic activity of the nanowire. In some embodiments, the amount of nanowire present on the support ranges from 1 to 100 parts by weight nanowires per 100 parts by weight of support or from 10 to 50 parts by weight nanowires per 100 parts by weight of support. In other embodiments, the amount of nanowire present on the support ranges from 100-200 parts of nanowires per 100 parts by weight of support, or 200-500 parts of nanowires per 100 parts by weight of support, or 500-1000 parts of nanowires per 100 parts by weight of support. Typically, heterogeneous catalysts are used either in their pure form or blended with inert materials, such as silica, alumina, etc. The blending with inert materials is used in order to reduce and/or control large temperature non-uniformities within the reactor bed often observed in the case of strongly exothermic (or endothermic) reactions. In the case of complex multistep reactions, such as the reaction to convert methane into ethylene (OCM), typical blending materials can selectively slow down or quench one or more of the reactions of the system and promote unwanted side reactions. For example, in the case of the oxidative coupling of methane, silica and alumina can quench the methyl radicals and thus prevent the formation of ethane. In certain aspects, the present disclosure provides a catalytic material which solves these problems typically associated with catalyst support material. Accordingly, in certain embodiments the catalytic activity of the catalytic material can be tuned by blending two or more catalysts and/or catalyst support materials. The blended catalytic material may comprise a catalytic nanowire as described herein and a bulk catalyst material and/or inert support material.

The blended catalytic materials comprise metal oxides, hydroxides, oxy-hydroxides, carbonates, oxalates of the groups 1-16, lanthanides, actinides or combinations thereof. For example, the blended catalytic materials may comprise a plurality of inorganic catalytic polycrystalline nanowires, as disclosed herein, and any one or more of straight nanowires, nanoparticles, bulk materials and inert support materials. Methods for preparing such other materials (e.g., straight nanowires) are known in the art and described in co-pending U.S. application Ser. No. 13/115,082, which application is hereby incorporated by reference in its entirety. Bulk materials are defined as any material in which no attempt to control the size and/or morphology was performed during its synthesis. The catalytic materials may be undoped or may be doped with any of the dopants described herein.

In one embodiment, the catalyst blend comprises at least one type 1 component and at least one type 2 component. Type 1 components comprise catalysts having a high OCM activity at moderately low temperatures and type 2 components comprise catalysts having limited or no OCM activity at these moderately low temperatures, but are OCM active at higher temperatures. For example, in some embodiments the type 1 component is a catalyst (e.g., nanowire) having high OCM activity at moderately low temperatures. For example, the type 1 component may comprise a C2 yield of greater than 5% or greater than 10% at temperatures less than 800° C., less than 700° C. or less than 600° C. The type 2 component may comprise a C2 yield less than 0.1%, less than 1% or less than 5% at temperatures less than 8000° C., less than 7000° C. or less than 600° C. The type 2 component may comprise a C2 yield of greater than 0.1%, greater than 1%, greater than 5% or greater than 10% at temperatures greater than 800° C., greater than 7000° C. or greater than 6000° C. Typical type 1 components include nanowires, for example polycrystalline nanowires as described herein, while typical type 2 components include bulk OCM catalysts and nanowire catalysts which only have good OCM activity at higher temperatures, for example greater than 800° C. Examples of type 2 components may include catalysts comprising MgO. The catalyst blend may further comprise inert support materials as described above (e.g., silica, alumina, silicon carbide, etc.).

In certain embodiments, the type 2 component acts as diluent in the same way an inert material does and thus helps reduce and/or control hot spots in the catalyst bed caused by the exothermic nature of the OCM reaction. However, because the type 2 component is an OCM catalyst, albeit not a particularly active one, it may prevent the occurrence of undesired side reactions, e.g. methyl radical quenching. Additionally, controlling the hotspots has the beneficial effect of extending the lifetime of the catalyst.

For example, it has been found that diluting active lanthanide oxide OCM catalysts (e.g., nanowires) with as much as a 10:1 ratio of MgO, which by itself is not an active OCM catalyst at the temperature which the lanthanide oxide operates, is a good way to minimize “hot spots” in the reactor catalyst bed, while maintaining the selectivity and yield performance of the catalyst. On the other hand, doing the same dilution with quartz SiO₂ is not effective because it appears to quench the methyl radicals which serve to lower the selectivity to C2s.

In yet another embodiment, the type 2 components are good oxidative dehydrogenation (ODH) catalysts at the same temperature that the type 1 components are good OCM catalysts. In this embodiment, the ethylene/ethane ratio of the resulting gas mixture can be tuned in favor of higher ethylene. In another embodiment, the type 2 components are not only good ODH catalysts at the same temperature the type 1 components are good OCM catalysts, but also have limited to moderate OCM activity at these temperatures.

In related embodiments, the catalytic performance of the catalytic material is tuned by selecting specific type 1 and type 2 components of a catalyst blend. In another embodiment, the catalytic performance is tuned by adjusting the ratio of the type 1 and type 2 components in the catalytic material. For example, the type 1 catalyst may be a catalyst for a specific step in the catalytic reaction, while the type 2 catalyst may be specific for a different step in the catalytic reaction. For example, the type 1 catalyst may be optimized for formation of methyl radicals and the type 2 catalyst may be optimized for formation of ethane or ethylene.

In other embodiments, the catalytic material comprises at least two different components (component 1, component 2, component 3, etc.). The different components may comprise different morphologies, e.g. nanowires, nanoparticles, bulk, etc. The different components in the catalyst material can be, but not necessarily, of the same chemical composition and the only difference is in the morphology and/or the size of the particles. This difference in morphology and particle size may result in a difference in reactivity at a specific temperature. Additionally, the difference in morphology and particle size of the catalytic material components is advantageous for creating a very intimate blending, e.g. very dense packing of the catalysts particles, which can have a beneficial effect on catalyst performance. Also, the difference in morphology and particle size of the blend components would allow for control and tuning of the macro-pore distribution in the reactor bed and thus its catalytic efficiency. An additional level of micro-pore tuning can be attained by blending catalysts with different chemical composition and different morphology and/or particle size. The proximity effect would be advantageous for the reaction selectivity.

Accordingly, in one embodiment the present disclosure provides the use of a catalytic material comprising a first catalytic nanowire and a bulk catalyst and/or a second catalytic nanowire in a catalytic reaction, for example the catalytic reaction may be OCM or ODH. In other embodiments, the first catalytic nanowire and the bulk catalyst and/or second catalytic nanowire are each catalytic with respect to the same reaction, and in other examples the first catalytic nanowire and the bulk catalyst and/or second catalytic nanowire have the same chemical composition.

In some specific embodiments of the foregoing, the catalytic material comprises a first catalytic nanowire and a second catalytic nanowire. Each nanowire can have completely different chemical compositions or they may have the same base composition and differ only by the doping elements. In other embodiments, each nanowire can have the same or a different morphology. For example, each nanowire can differ by the nanowire size (length and/or aspect ratio), by ratio of actual/effective length, by chemical composition or any combination thereof. Furthermore, the first and second nanowires may each be catalytic with respect to the same reaction but may have different activity. Alternatively, each nanowire may catalyze different reactions.

In a related embodiment, the catalytic material comprises a first catalytic nanowire and a bulk catalyst. The first nanowire and the bulk catalyst can have completely different chemical compositions or they may have the same base composition and differ only by the doping elements. Furthermore, the first nanowire and the bulk catalyst may each be catalytic with respect to the same reaction but may have different activity. Alternatively, the first nanowire and the bulk catalyst may catalyze different reactions.

In yet other embodiments of the foregoing, the catalytic nanowire has a catalytic activity in the catalytic reaction, which is greater than a catalytic activity of the bulk catalyst in the catalytic reaction at the same temperature. In still other embodiments, the catalytic activity of the bulk catalyst in the catalytic reaction increases with increasing temperature.

OCM catalysts may be prone to hotspots due to the very exothermic nature of the OCM reaction. Diluting such catalysts helps to manage the hotspots. However, the diluent needs to be carefully chosen so that the overall performance of the catalyst is not degraded. Silicon carbide for example can be used as a diluent with little impact on the OCM selectivity of the blended catalytic material whereas using silica as a diluent significantly reduces OCM selectivity. The good heat conductivity of SiC is also beneficial in minimizing hot spots. As noted above, use of a catalyst diluents or support material that is itself OCM active has significant advantages over more traditional diluents such as silica and alumina, which can quench methyl radicals and thus reduce the OCM performance of the catalyst. An OCM active diluent is not expected to have any adverse impact on the generation and lifetime of methyl radicals and thus the dilution should not have any adverse impact on the catalyst performance. Thus embodiments of the invention include catalyst compositions comprising an OCM catalyst (e.g., any of the disclosed nanowire catalysts) in combination with a diluent or support material that is also OCM active. Methods for use of the same in an OCM reaction are also provided.

In some embodiments, the above diluent comprises alkaline earth metal compounds, for example alkaline metal oxides, carbonates, sulfates or phosphates. Examples of diluents useful in various embodiments include, but are not limited to, MgO, MgCO₃, MgSO₄, Mg₃(PO₄)₂, MgAl₂O₄, CaO, CaCO₃, CaSO₄, Ca₃(PO₄)₂, CaAl₂O₄, SrO, SrCO₃, SrSO₄, Sr₃(PO₄)₂, SrAl₂O₄, BaO, BaCO₃, BaSO₄, Ba₃(PO₄)₂, BaAl₂O₄ and the like. Most of these compounds are very cheap, especially MgO, CaO, MgCO₃, CaCO₃, SrO, SrCO₃ and thus very attractive for use as diluents from an economic point of view. Additionally, the magnesium, calcium and strontium compounds are environmentally friendly too. Accordingly, an embodiment of the invention provides a catalytic material comprising a catalytic nanowire in combination with a diluent selected from one or more of MgO, MgC₀₃, MgSO₄, Mg₃(PO₄)₂, CaO, CaCO₃, CaSO₄, Ca₃(PO₄)₂, SrO, SrCO₃, SrSO₄, Sr₃(PO₄)₂, BaO, BaCO₃, BaSO₄, Ba₃(PO₄)₂. In some specific embodiments the diluents is MgO, CaO, SrO, MgCO₃, CaCO₃, SrCO₃ or combination thereof. Methods for use of the foregoing catalytic materials in an OCM reaction are also provided. The methods comprise converting methane to ethane and or ethylene in the presence of the catalytic materials.

The above diluents and supports may be employed in any number of methods. For example, in some embodiments a support (e.g., MgO, CaO, CaCO₃, SrCO₃) may be used in the form of a pellet or monolith (e.g., honeycomb) structure, and the nanowire catalysts may be impregnated or supported thereon. In other embodiments, a core/shell arrangement is provided and the support material may form part of the core or shell. For example, a core of MgO, CaO, CaCO₃ or SrCO₃ may be coated with a shell of any of the disclosed nanowire compositions.

In some embodiments, the diluent has a morphology selected from bulk (e.g. commercial grade), nano (nanowires, nanorods, nanoparticles, etc.) or combinations thereof.

In some embodiments, the diluent has none to moderate catalytic activity at the temperature the OCM catalyst is operated. In some other embodiments, the diluent has moderate to large catalytic activity at a temperature higher than the temperature the OCM catalyst is operated. In yet some other embodiments, the diluent has none to moderate catalytic activity at the temperature the OCM catalyst is operated and moderate to large catalytic activity at temperatures higher than the temperature the OCM catalyst is operated. Typical temperatures for operating an OCM reaction according to the present disclosure are 800° C. or lower, 750° C. or lower, 700° C. or lower, 650° C. or lower, 600° C. or lower and 550° C. or lower.

For example, CaCO₃ is a relatively good OCM catalyst at T>750° C. (50% selectivity, >20% conversion) but has essentially no activity below 700° C. Experiments performed in support of the present invention showed that dilution of Nd₂O₃ straight nanowires with CaCO₃ or SrCO₃ (bulk) showed no degradation of OCM performance and, in some cases, even better performance than the neat catalyst.

In some embodiments, the diluent portion in the catalyst/diluent mixture is 0.01%, 10%, 30%, 50%, 70%, 90% or 99.99% (weight percent) or any other value between 0.01% and 99.9%. In some embodiments, the dilution is performed with the OCM catalyst ready to go, e.g. after calcination. In some other embodiments, the dilution is performed prior to the final calcination of the catalyst, i.e. the catalyst and the diluent are calcined together. In yet some other embodiments, the dilution can be done during the synthesis as well, so that, for example, a mixed oxide is formed.

In some embodiments, the catalyst/diluent mixture comprises more than one catalyst and/or more than one diluent. In some other embodiments, the catalyst/diluent mixture is pelletized and sized, or made into shaped extrudates or deposited on a monolith or foam, or is used as it is. Methods of the invention include taking advantage of the very exothermic nature of OCM by diluting the catalyst with another catalyst that is (almost) inactive in the OCM reaction at the operating temperature of the first catalyst but active at higher temperature. In these methods, the heat generated by the hotspots of the first catalyst will provide the necessary heat for the second catalyst to become active.

For ease of illustration, the above description of catalytic materials often refers to OCM; however, such catalytic materials find utility in other catalytic reactions including but not limited to: oxidative dehydrogenation (ODH) of alkanes to their corresponding alkenes, selective oxidation of alkanes and alkenes and alkynes, oxidation of co, dry reforming of methane, selective oxidation of aromatics, Fischer-Tropsch, combustion of hydrocarbons, etc.

4. Preparation of Catalytic Materials

The catalytic materials can be prepared according to any number of methods known in the art. For example, the catalytic materials can be prepared after preparation of the individual components by mixing the individual components in their dry form, e.g. blend of powders, and optionally, ball milling can be used to reduce particle size and/or increase mixing. Each component can be added together or one after the other to form layered particles. Alternatively, the individual components can be mixed prior to calcination, after calcination or by mixing already calcined components with uncalcined components. The catalytic materials may also be prepared by mixing the individual components in their dry form and optionally pressing them together into a “pill” followed by calcination to above 400° C.

In other examples, the catalytic materials are prepared by mixing the individual components with one or more solvents into a suspension or slurry, and optional mixing and/or ball milling can be used to maximize uniformity and reduce particle size. Examples of slurry solvents useful in this context include, but are not limited to: water, alcohols, ethers, carboxylic acids, ketones, esters, amides, aldehydes, amines, alkanes, alkenes, alkynes, aromatics, etc. In other embodiments, the individual components are deposited on a supporting material such as silica, alumina, magnesia, activated carbon, and the like, or by mixing the individual components using a fluidized bed granulator. Combinations of any of the above methods may also be used.

The catalytic materials may optionally comprise a dopant as described in more detail below. In this respect, doping material(s) may be added during preparation of the individual components, after preparation of the individual components but before drying of the same, after the drying step but before calcinations or after calcination. If more than one doping material is used, each dopant can be added together or one after the other to form layers of dopants.

Doping material(s) may also be added as dry components and optionally ball milling can be used to increase mixing. In other embodiments, doping material(s) are added as a liquid (e.g. solution, suspension, slurry, etc.) to the dry individual catalyst components or to the blended catalytic material. The amount of liquid may optionally be adjusted for optimum wetting of the catalyst, which can result in optimum coverage of catalyst particles by doping material. Mixing and/or ball milling can also be used to maximize doping coverage and uniform distribution. Alternatively, doping material(s) are added as a liquid (e.g. solution, suspension, slurry, etc.) to a suspension or slurry of the catalyst in a solvent. Mixing and/or ball milling can be used to maximize doping coverage and uniform distribution. Incorporation of dopants can also be achieved using any of the methods described elsewhere herein.

As noted below, an optional calcination step usually follows an optional drying step at T<200 C (typically 60-120 C) in a regular oven or in a vacuum oven. Calcination may be performed on the individual components of the catalytic material or on the blended catalytic material. Calcination is generally performed in an oven/furnace at a temperature higher than the minimum temperature at which at least one of the components decomposes or undergoes a phase transformation and can be performed in inert atmosphere (e.g. N₂, Ar, He, etc.), oxidizing atmosphere (air, O₂, etc.) or reducing atmosphere (H₂, H₂/N₂, H₂/Ar, etc.). The atmosphere may be a static atmosphere or a gas flow and may be performed at ambient pressure, at p<1 atm, in vacuum or at p>1 atm. High pressure treatment (at any temperature) may also be used to induce phase transformation including amorphous to crystalline. Calcinations may also be performed using microwave heating.

Calcination is generally performed in any combination of steps comprising ramp up, dwell and ramp down. For example, ramp to 500° C., dwell at 500° C. for 5 h, ramp down to RT. Another example includes ramp to 100° C., dwell at 100° C. for 2 h, ramp to 300° C., dwell at 300° C. for 4 h, ramp to 550° C., dwell at 550° C. for 4 h, ramp down to RT. Calcination conditions (pressure, atmosphere type, etc.) can be changed during the calcination. In some embodiments, calcination is performed before preparation of the blended catalytic material (i.e., individual components are calcined), after preparation of the blended catalytic material but before doping, after doping of the individual components or blended catalytic material. Calcination may also be performed multiple times, e.g. after catalyst preparation and after doping.

The catalytic materials may be incorporated into a reactor bed for performing any number of catalytic reactions (e.g., OCM, ODH and the like). Accordingly, in one embodiment the present disclosure provides a catalytic material as disclosed herein in contact with a reactor and/or in a reactor bed. For example, the reactor may be for performing an OCM reaction, may be a fixed bed reactor and may have a diameter greater than 1 inch. In this regard, the catalytic material may be packed neat (without diluents) or diluted with an inert material (e.g., sand, silica, alumina, etc.) The catalyst components may be packed uniformly forming a homogeneous reactor bed.

The particle size of the individual components within a catalytic material may also alter the catalytic activity, and other properties, of the same. Accordingly, in one embodiment, the catalyst is milled to a target average particle size or the catalyst powder is sieved to select a particular particle size. In some aspects, the catalyst powder may be pressed into pellets and the catalyst pellets can be optionally milled and or sieved to obtain the desired particle size distribution.

In some embodiments, the catalyst materials, alone or with binders and/or diluents, can be configured into larger aggregate forms, such as pellets, extrudates, or other aggregations of catalyst particles. For ease of duscussion, such larger forms are generally referred to herein as “pellets”. Such pellets may optionally include a binder and/or support material; however, the present inventors have surprisingly found that the disclosed nanowires are particularly suited to used in the form of a pellet without a binder and/or support material. Accordingly, one embodiment of the disclosure provides a catalytic material in the absence of a binder. In this regard, the morphology of the disclosed nanowires (either bent or straight, etc.) is believed to contribute to the nanowires' ability to be pressed into pellets without the need for a binder. Catalytic materials without binders are simpler, less complex and cheaper than corresponding materials with binders and thus offer certain advantages.

In some instances, catalytic materials may be prepared using a “sacrificial binder” or support. Because of their special properties, the nanowires allow for preparation of catalytic material forms (e.g. pellets) without the use of a binder. A “sacrificial” binder can be used in order to create unique microporosity in pellets or extrudates. After removing the sacrificial binder, the structural integrity of the catalyst is ensured by the special binding properties of the nanowires and the resulting catalytic material has unique microporosity as a result of removing the binder. For example, in some embodiments a catalytic nanowire may be prepared with a binder and then the binder removed by any number of techniques (e.g., combustion, calcinations, acid erosion, etc.). This method allows for design and preparation of catalytic materials having unique microporosity (i.e., the microporosity is a function of size, etc. of the sacrificial binder). The ability to prepare different forms (e.g., pellets) of the nanowires without the use of binder is not only useful for preparation of catalytic materials from the nanowires, but also allows the nanowires to be used as support materials (or both catalytic and support material). Sacrificial binders and techniques useful in this regard include sacrificial cellulosic fibers or other organic polymers that can be easily removed by calcination, non-sacrificial binders and techniques useful inthis regard include, colloidal oxide binders such as Ludox Silica or Nyacol colloidal zirconia that can also be added to strengthen the formed aggregate when needed. Sacrificial binders are added to increase macro-porosity (pores larger than 20 nm diameter) of the catalytic materials. Accordingly, in some embodiments the catalytic materials comprise pores greater than 20 nm in diameter, greater than 50 nm in diameter, greater than 75 nm in diameter, greater than 100 nm in diameter or greater than 150 nm in diameter.

Catalytic materials also include any of the disclosed nanowires disposed on or adhered to a solid support. For example, the nanowires may be adhered to the surface of a monolith support. As with the binder-less materials discussed above, in these embodiments the nanowires may be adhered to the surface of the monolith in the absence of a binder due to their unique morphology and packing properties. Monoliths include honeycomb-type structures, foams and other catalytic support structures derivable by one skilled in the art. In one embodiment, the support is a honeycomb matrix formed from silicon carbide, and the support further comprises catalytic nanowires disposed on the surface.

As the OCM reaction is very exothermic, it can be desirable to reduce the rate of conversion per unit volume of reactor in order to avoid run away temperature rise in the catalyst bed that can result in hot spots affecting performance and catalyst life. One way to reduce the OCM reaction rate per unit volume of reactor is to spread the active catalyst onto an inert support with interconnected large pores as in ceramic or metallic foams (including metal alloys having reduced reactivity with hydrocarbons under OCM reaction conditions) or having arrays of channel as in honeycomb structured ceramic or metal assembly.

In one embodiment, a catalytic material comprising a catalytic nanowire as disclosed herein supported on a structured support is provided. Examples of such structure supports include, but are not limited to, metal foams, Silicon Carbide or Alumina foams, corrugated metal foil arranged to form channel arrays, extruded ceramic honeycomb, for example Cordierite (available from Corning or NGK ceramics, USA), Silicon Carbide or Alumina.

Active catalyst loading on the structured support ranges from 1 to 500 mg per ml of support component, for example from 5 to 100 mg per ml of structure support. Cell densities on honeycomb structured support materials may range from 100 to 900 CPSI (cell per square inch), for example 200 to 600 CPSI. Foam densities may range from 10 to 100 PPI (pore per inch), for example 20 to 60 PPI.

In other embodiments, the exotherm of the OCM reaction may be at least partially controlled by blending the active catalytic material with catalytically inert material, and pressing or extruding the mixture into shaped pellets or extrudates. In some embodiments, these mixed particles may then be loaded into a pack-bed reactor. The Extrudates or pellets comprise between 30% to 70% pore volume with 5% to 50% active catalyst weight fraction. Useful inert materials in this regard include, but are not limited to MgO, CaO, Al₂O₃, SiC and cordierite.

In addition to reducing the potential for hot spots within the catalytic reactor, another advantage of using a structured ceramic with large pore volume as a catalytic support is reduced flow resistance at the same gas hourly space velocity versus a pack-bed containing the same amount of catalyst.

Yet another advantage of using such supports is that the structured support can be used to provide features difficult to obtain in a pack-bed reactor. For example the support structure can improve mixing or enabling patterning of the active catalyst depositions through the reactor volume. Such patterning can consist of depositing multiple layers of catalytic materials on the support in addition to the OCM active component in order to affect transport to the catalyst or combining catalytic functions as adding O2-ODH activity, CO2-OCM activity or CO2-ODH activity to the system in addition to O2-OCM active material. Another patterning strategy can be to create bypass within the structure catalyst essentially free of active catalyst to limit the overall conversion within a given supported catalyst volume.

Yet another advantage is reduced heat capacity of the bed of the structured catalyst over a pack bed a similar active catalyst loading therefore reducing startup time.

Nanowire shaped catalysts are particularly well suited for incorporation into pellets or extrudates or deposition onto structured supports. Nanowire aggregates forming a mesh type structure can have good adhesion onto rough surfaces.

The mesh like structure can also provide improved cohesion in composite ceramic improving the mechanical properties of pellets or extrudates containing the nanowire shaped catalyst particles.

Alternatively, such nanowire on support or in pellet form approaches can be used for other reactions besides OCM, such as ODH, dry methane reforming, FT, and all other catalytic reactions.

In yet another embodiment, the catalysts are packed in bands forming a layered reactor bed. Each layer is composed by either a catalyst of a particular type, morphology or size or a particular blend of catalysts. In one embodiment, the catalysts blend may have better sintering properties, i.e. lower tendency to sinter, then a material in its pure form. Better sintering resistance is expected to increase the catalyst's lifetime and improve the mechanical properties of the reactor bed.

In yet other embodiments, the disclosure provides a catalytic material comprising one or more different catalysts. The catalysts may be a nanowire as disclosed herein and a different catalyst for example a bulk catalysts. Mixtures of two or more nanowire catalysts are also contemplated. The catalytic material may comprise a catalyst, for example a nanowire catalyst, having good OCM activity and a catalyst having good activity in the ODH reaction. Either one or both of these catalysts may be nanowires as disclosed herein.

On skilled in the art will recognize that various combinations or alternatives of the above methods are possible, and such variations are also included within the scope of the present disclosure.

5. Dopants

In further embodiments, the disclosure provides nanowires comprising a dopant (i.e., doped nanowires). As noted above, dopants or doping agents are impurities added to or incorporated within a catalyst to optimize catalytic performance (e.g., increase or decrease catalytic activity). As compared to the undoped catalyst, a doped catalyst may increase or decrease the selectivity, conversion, and/or yield of a catalytic reaction. In one embodiment, nanowire dopants comprise one or more metal elements, semi-metal elements, non-metal elements or combinations thereof. Although oxygen is included in the group of nonmetal elements, in certain embodiments oxygen is not considered a dopant. For example, certain embodiments are directed to nanowires comprising two, three or even four or more dopants, and the dopants are non-oxygen dopants. Thus in these embodiments, a metal oxide nanowire is not considered to be a metal nanowire doped with oxygen. Analogously, in the case of mixed oxides (i.e., M1_(x)M2_(y)O_(z)), both the metal elements and oxygen are considered a part of the base catalyst (nanowire) and are not included in the total number of dopants.

The dopant may be present in any form and may be derived from any suitable source of the element (e.g., chlorides, bromides, iodides, nitrates, oxynitrates, oxyhalides, acetates, formates, hydroxides, carbonates, phosphates, sulfates, alkoxides, and the like.). In some embodiments, the nanowire dopant is in elemental form. In other embodiments, the nanowire dopant is in reduced or oxidized form. In other embodiments, the nanowire dopant comprises an oxide, hydroxide, carbonate, nitrate, acetate, sulfate, formate, oxynitrate, halide, oxyhalide or hydroxyhalide of a metal element, semi-metal element or non-metal element or combinations thereof.

In one embodiment, the nanowires comprise one or more metal elements selected from Groups 1-7, lanthanides, actinides or combinations thereof in the form of an oxide and further comprise one or more dopants, wherein the one or more dopants comprise metal elements, semi-metal elements, non-metal elements or combinations thereof. In another embodiment, the nanowires comprise one or more metal elements selected from group 1 in the form of an oxide and further comprise one or more dopants, wherein the one or more dopants comprise metal elements, semi-metal elements, non-metal elements or combinations thereof. In another embodiment, the nanowires comprise one or more metal elements selected from group 2 in the form of an oxide and further comprise one or more dopants, wherein the one or more dopants comprise metal elements, semi-metal elements, non-metal elements or combinations thereof. In another embodiment, the nanowires comprise one or more metal elements selected from group 3 in the form of an oxide and further comprise one or more dopants, wherein the one or more dopants comprise metal elements, semi-metal elements, non-metal elements or combinations thereof. In another embodiment, the nanowires comprise one or more metal elements selected from group 4 in the form of an oxide and further comprise one or more dopants, wherein the one or more dopants comprise metal elements, semi-metal elements, non-metal elements or combinations thereof. In another embodiment, the nanowires comprise one or more metal elements selected from group 5 in the form of an oxide and further comprise one or more dopants, wherein the one or more dopants comprise metal elements, semi-metal elements, non-metal elements or combinations thereof. In another embodiment, the nanowires comprise one or more metal elements selected from group 6 in the form of an oxide and further comprise one or more dopants, wherein the one or more dopants comprise metal elements, semi-metal elements, non-metal elements or combinations thereof. In another embodiment, the nanowires comprise one or more metal elements selected from group 7 in the form of an oxide and further comprise one or more dopants, wherein the one or more dopants comprise metal elements, semi-metal elements, non-metal elements or combinations thereof. In another embodiment, the nanowires comprise one or more metal elements selected from lanthanides in the form of an oxide and further comprise one or more dopants, wherein the one or more dopants comprise metal elements, semi-metal elements, non-metal elements or combinations thereof. In another embodiment, the nanowires comprise one or more metal elements selected from actinides in the form of an oxide and further comprise one or more dopants, wherein the one or more dopants comprise metal elements, semi-metal elements, non-metal elements or combinations thereof.

For example, in one embodiment, the nanowire dopant comprises Li, Li₂CO₃, LiOH, Li₂O, LiCl, LiNO₃, Na, Na₂CO₃, NaOH, Na₂O, NaCl, NaNO₃, K, K₂CO₃, KOH, K₂O, KCl, KNO₃, Rb, Rb₂CO₃, RbOH, Rb₂O, RbCl, RbNO₃, Cs, Cs₂CO₃, CsOH, Cs₂O, CsCl, CsNO₃, Mg, MgCO₃, Mg(OH)₂, MgO, MgCl₂, Mg(NO₃)₂, Ca, CaO, CaCO₃, Ca(OH)₂, CaCl₂, Ca(NO₃)₂, Sr, SrO, SrCO₃, Sr(OH)₂, SrCl₂, Sr(NO₃)₂, Ba, BaO, BaCO₃, Ba(OH)₂, BaCl₂, Ba(NO₃)₂, La, La₂O₃, La₂(CO₃)₃, La(OH)₃, LaCl₃, La(NO₃)₂, Nd, Nd₂O₃, Nd₂(CO₃)₃, Nd(OH)₃, NdCl₃, Nd(NO₃)₂, Sm, Sm₂O₃, Sm₂(CO₃)₃, Sm(OH)₃, SmCl₃, Sm(NO₃)₂, Eu, Eu₂O₃, Eu₂(CO₃)₃, Eu(OH)₃, EuCl₃, Eu(NO₃)₂, Gd, Gd₂O₃, Gd₂(CO₃)₃, Gd(OH)₃, GdCl₃, Gd(NO₃)₂, Ce, Ce(OH)₄, CeO₂, Ce₂O₃, Ce(CO₃)₂, CeCl₄, Ce(NO₃)₂, Th, ThO₂, ThCl₄, Th(OH)₄, Zr, ZrO₂, ZrCl₄, Zr(OH)₄, ZrOCl₂, Zr(CO₃)₂, ZrOCO₃, ZrO(NO₃)₂, P, phosphorous oxides, phosphorous chlorides, phosphorous carbonates, Ni, nickel oxides, nickel chlorides, nickel carbonates, nickel hydroxides, Nb, niobium oxides, niobium chlorides, niobium carbonates, niobium hydroxides, Au, gold oxides, gold chlorides, gold carbonates, gold hydroxides, Mo, molybdenum oxides, molybdenum chlorides, molybdenum carbonates, molybdenum hydroxides, tungsten chlorides, tungsten carbonates, tungsten hydroxides, Cr, chromium oxides, chromium chlorides, chromium hydroxides, Mn, manganese oxides, manganese chlorides, manganese hydroxides, Zn, ZnO, ZnCl₂, Zn(OH)₂, B, borates, BCl₃, N, nitrogen oxides, nitrates, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, In, Y, Sc, Al, Cu, Cs, Ga, Hf, Fe, Ru, Rh, Be, Co, Sb, V, Ag, Te, Pd, Tb, Ir, Rb or combinations thereof. In other embodiments, the nanowire dopant comprises Li, Na, K, Rb, Cs, Mg, Ca, Sr, Eu, In, Nd, Sm, Ce, Gd, Tb, Er, Tm, Yb, Y, Sc or combinations thereof.

In other embodiments, the nanowire dopant comprises Li, Li₂O, Na, Na₂O, K, K₂O, Mg, MgO, Ca, CaO, Sr, SrO, Ba, BaO, La, La₂O₃, Ce, CeO₂, Ce₂O₃, Th, ThO₂, Zr, ZrO₂, P, phosphorous oxides, Ni, nickel oxides, Nb, niobium oxides, Au, gold oxides, Mo, molybdenum oxides, Cr, chromium oxides, Mn, manganese oxides, Zn, ZnO, B, borates, N, nitrogen oxides or combinations thereof. In other embodiments, the nanowire dopant comprises Li, Na, K, Mg, Ca, Sr, Ba, La, Ce, Th, Zr, P, Ni, Nb, Au, Mo, Cr, Mn, Zn, B, N or combinations thereof. In other embodiments, the nanowire dopant comprises Li₂O, Na₂O, K₂O, MgO, CaO, SrO, BaO, La₂O₃, CeO₂, Ce₂O₃, ThO₂, ZrO₂, phosphorous oxides, nickel oxides, niobium oxides, gold oxides, molybdenum oxides, chromium oxides, manganese oxides, ZnO, borates, nitrogen oxides or combinations thereof. In further embodiments, the dopant comprises Sr or Li. In other specific embodiments, the nanowire dopant comprises La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, In, Y, Sc or combinations thereof. In other specific embodiments, the nanowire dopant comprises Li, Na, K, Mg, Ca, Ba, Sr, Eu, Sm, Co or Mn.

In certain embodiments, the dopant comprises an element from group 1. In some embodiments, the dopant comprises lithium. In some embodiments, the dopant comprises sodium. In some embodiments, the dopant comprises potassium. In some embodiments, the dopant comprises rubidium. In some embodiments, the dopant comprises caesium.

In some embodiments the nanowires comprise a lanthanide element and are doped with a dopant from group 1, group 2, or combinations thereof. For example, in some embodiments, the nanowires comprise a lanthanide element and are doped with lithium. In other embodiments, the nanowires comprise a lanthanide element and are doped with sodium. In other embodiments, the nanowires comprise a lanthanide element and are doped with potassium. In other embodiments, the nanowires comprise a lanthanide element and are doped with rubidium. In other embodiments, the nanowires comprise a lanthanide element and are doped with caesium. In other embodiments, the nanowires comprise a lanthanide element and are doped with beryllium. In other embodiments, the nanowires comprise a lanthanide element and are doped with magnesium. In other embodiments, the nanowires comprise a lanthanide element and are doped with calcium. In other embodiments, the nanowires comprise a lanthanide element and are doped with strontium. In other embodiments, the nanowires comprise a lanthanide element and are doped with barium.

In some embodiments the nanowires comprise a transition metal tungstate (e.g., Mn/W and the like) and are doped with a dopant from group 1, group 2, or combinations thereof. For example, in some embodiments, the nanowires comprise a transition metal tungstate and are doped with lithium. In other embodiments, the nanowires comprise a transition metal tungstate and are doped with sodium. In other embodiments, the nanowires comprise a transition metal tungstate and are doped with potassium. In other embodiments, the nanowires comprise a transition metal tungstate and are doped with rubidium. In other embodiments, the nanowires comprise a transition metal tungstate and are doped with caesium. In other embodiments, the nanowires comprise a transition metal tungstate and are doped with beryllium. In other embodiments, the nanowires comprise a transition metal tungstate and are doped with magnesium. In other embodiments, the nanowires comprise a transition metal tungstate and are doped with calcium. In other embodiments, the nanowires comprise a transition metal tungstate and are doped with strontium. In other embodiments, the nanowires comprises a transition metal tungstate and are doped with barium.

In some embodiments the nanowires comprise Mn/Mg/O and are doped with a dopant from group 1, group 2, group 7, group 8, group 9 or group 10 or combinations thereof. For example, in some embodiments, the nanowires comprise Mn/Mg/O and are doped with lithium. In other embodiments, the nanowires comprise Mn/Mg/O and are doped with sodium. In other embodiments, the nanowires comprise Mn/Mg/O and are doped with potassium. In other embodiments, the nanowires comprise Mn/Mg/O and are doped with rubidium. In other embodiments, the nanowires comprise Mn/Mg/O and are doped with caesium. In other embodiments, the nanowires comprise Mn/Mg/O and are doped with beryllium. In other embodiments, the nanowires comprise Mn/Mg/O and are doped with magnesium. In other embodiments, the nanowires comprise Mn/Mg/O and are doped with calcium. In other embodiments, the nanowires comprise Mn/Mg/O and are doped with strontium. In other embodiments, the nanowires comprise Mn/Mg/O and are doped with barium.

In yet some other embodiments, the nanowires comprise Mn/Mg/O and are doped with manganese. In other embodiments, the nanowires comprise Mn/Mg/O and are doped with technetium. In other embodiments, the nanowires comprise Mn/Mg/O and are doped with rhenium. In other embodiments, the nanowires comprise Mn/Mg/O and are doped with iron. In other embodiments, the nanowires comprise Mn/Mg/O and are doped with ruthenium. In other embodiments, the nanowires comprise Mn/Mg/O and are doped with osmium. In other embodiments, the nanowires comprise Mn/Mg/O and are doped with cobalt. In other embodiments, the nanowires comprise Mn/Mg/O and are doped with rhodium. In other embodiments, the nanowires comprise Mn/Mg/O and are doped with iridium. In other embodiments, the nanowires comprise Mn/Mg/O and are doped with nickel. In other embodiments, the nanowires comprise Mn/Mg/O and are doped with palladium. In other embodiments, the nanowires comprise Mn/Mg/O and are doped with platinum.

As noted above, the present inventors have determined that certain nanowire catalysts comprising rare earth elements(e.g., rare earth oxides) are useful as catalysts in a number of reactions, for example the OCM reaction. In certain embodiments the rare earth element is La, Nd, Eu, Sm, Yb, Gd or Y. In some embodiments, the rare earth element is La. In other embodiments, the rare earth element is Nd. In other embodiments, the rare earth element is Eu. In other embodiments, the rare earth element is Sm. In other embodiments, the rare earth element is Yb. In other embodiments, the rare earth element is Gd. In other embodiments, the rare earth element is Y.

In certain embodiments of the nanowire catalysts comprising rare earth elements, the catalyst may further comprise a dopant selected from alkaline earth (Group 2) elements. For example, in some embodiments the dopant is selected from Be, Mg, Ca, Sr and Ba. In other embodiments, the dopant is Be. In other embodiments, the dopant is Ca. In other embodiments, the dopant is Sr. In other embodiments, the dopant is Ba.

In some embodiments, these rare earth compositions comprise La₂O₃, Nd₂O₃, Yb₂O₃, Eu₂O₃, Sm₂O₃, Y₂O₃, Ce₂O₃, Pr₂O₃, Ln1_(4-x)Ln2_(x)O₆, La_(4-x)Ln1_(x)O₆, La_(4-x)Nd_(x)O₆, La₃NdO₆, LaNd₃O₆, La_(1.5)Nd_(2.5)O₆, La_(2.5)Nd_(1.5)O₆, La_(3.2)Nd_(0.8)O₆, La_(3.5)Nd_(0.5)O₆, La_(3.8)Nd_(0.2)O₆, Y—La, Zr—La, Pr—La or Ce—La or combinations thereof, wherein Ln1 and Ln2 are each independently a lanthanide element, wherein Ln1 and Ln2 are not the same and x is a number ranging from greater than 0 to less than 4.

Further, Applicants have discovered that certain doping combinations, when combined with the above rare earth compositions, serve to enhance the catalytic activity of the nanowires in certain catalytic reactions, for example OCM. The dopants may be present in various levels (e.g., w/w), and the nanowires may be prepared by any number of methods. Various aspects of the above nanowires are provided in the following paragraphs and in Tables 9-12.

In certain embodiments, the above rare earth compositions comprise a strontium dopant and at least one more additional dopant selected from group 1, 4-6, 13 and lanthanides. For example, in some embodiments the additional dopant is Hf, K, Zr, Ce, Tb, Pr, W, Rb, Ta, B or combinations thereof. In other embodiments, the dopant comprises Sr/Hf, Sr/Hf/K, Sr/Zr, Sr/Zr/K, Sr/Ce, Sr/Ce/K, Sr/Tb, Sr/Tb/K, Sr/Pr, Sr/Pr/K, Sr/W, Sr/Hf/Rb, Sr/Ta or Sr/B. In some other embodiments, the foregoing rare earth nanowires comprise La₂O₃ or La₃NdO₆.

In other embodiments, the nanowire catalysts comprise a rare earth oxide and dopants selected from at least one of the following combinations Eu/Na, Sr/Na, Mg/Na, Sr/W, K/La, K/Na, Li/Cs, Li/Na, Zn/K, Li/K, Rb/Hf, Ca/Cs, Hf/Bi, Sr/Sn, Sr/W, Sr/Nb, Zr/W, Y/W, Na/W, Bi/W, Bi/Cs, Bi/Ca, Bi/Sn, Bi/Sb, Ge/Hf, Hf/Sm, Sb/Ag, Sb/Bi, Sb/Au, Sb/Sm, Sb/Sr, Sb/W, Sb/Hf, Sb/Yb, Sb/Sn, Yb/Au, Yb/Ta, Yb/W, Yb/Sr, Yb/Pb, Yb/W, Yb/Ag, Au/Sr, W/Ge, Ta/Hf, W/Au, Ca/W, Au/Re, Sm/Li, La/K, Zn/Cs, Zr/Cs, Ca/Ce, Li/Sr, Cs/Zn, Dy/K, La/Mg, In/Sr, Sr/Cs, Ga/Cs, Lu/Fe, Sr/Tm, La/Dy, Mg/K, Zr/K, Li/Cs, Sm/Cs, In/K, Lu/TI, Pr/Zn, Lu/Nb, Na/Pt, Na/Ce, Ba/Ta, Cu/Sn, Ag/Au, Al/Bi, Al/Mo, Al/Nb, Au/Pt, Ga/Bi, Mg/W, Pb/Au, Sn/Mg, Zn/Bi, Gd/Ho, Zr/Bi, Ho/Sr, Ca/Sr, Sr/Pb and Sr/Hf.

In still other embodiments, the nanowire catalysts comprise a rare earth oxide and dopants selected from at least one of the following combinations La/Nd, La/Sm, La/Ce, La/Sr, Eu/Na, Eu/Gd, Ca/Na, Eu/Sm, Eu/Sr, Mg/Sr, Ce/Mg, Gd/Sm, Sr/W, Sr/Ta, Au/Re, Au/Pb, Bi/Hf, Sr/Sn or Mg/N, Ca/S, Rb/S, Sr/Nd, Eu/Y, Mg/Nd, Sr/Na, Nd/Mg, La/Mg, Yb/S, Mg/Na, Sr/W, K/La, K/Na, Li/Cs, Li/Na, Zn/K, Li/K, Rb/Hf, Ca/Cs, Hf/Bi, Sr/Sn, Sr/W, Sr/Nb, Zr/W, Y/W, Na/W, Bi/W, Bi/Cs, Bi/Ca, Bi/Sn, Bi/Sb, Ge/Hf, Hf/Sm, Sb/Ag, Sb/Bi, Sb/Au, Sb/Sm, Sb/Sr, Sb/W, Sb/Hf, Sb/Yb, Sb/Sn, Yb/Au, Yb/Ta, Yb/W, Yb/Sr, Yb/Pb, Yb/W, Yb/Ag, Au/Sr, W/Ge, Ta/Hf, W/Au, Ca/W, Au/Re, Sm/Li, La/K, Zn/Cs, Zr/Cs, Ca/Ce, Li/Sr, Cs/Zn, Dy/K, La/Mg, In/Sr, Sr/Cs, Ga/Cs, Lu/Fe, Sr/Tm, La/Dy, Mg/K, Zr/K, Li/Cs, Sm/Cs, In/K, Lu/TI, Pr/Zn, Lu/Nb, Na/Pt, Na/Ce, Ba/Ta, Cu/Sn, Ag/Au, Al/Bi, Al/Mo, Al/Nb, Au/Pt, Ga/Bi, Mg/W, Pb/Au, Sn/Mg, Zn/Bi, Gd/Ho, Zr/Bi, Ho/Sr, Ca/Sr, Sr/Pb and Sr/Hf.

In other embodiments of the foregoing rare earth oxide nanowire catalysts, the nanowire catalysts comprise a combination of two doping elements.

In some embodiments, the combination of two doping elements is La/Nd. In other embodiments, the combination of two doping elements is La/Sm. In other embodiments, the combination of two doping elements is La/Ce. In other embodiments, the combination of two doping elements is La/Sr. In other embodiments, the combination of two doping elements is Eu/Na. In other embodiments, the combination of two doping elements is Eu/Gd. In other embodiments, the combination of two doping elements is Ca/Na. In other embodiments, the combination of two doping elements is Eu/Sm. In other embodiments, the combination of two doping elements is Eu/Sr. In other embodiments, the combination of two doping elements is Mg/Sr. In other embodiments, the combination of two doping elements is Ce/Mg. In other embodiments, the combination of two doping elements is Gd/Sm. In other embodiments, the combination of two doping elements is Sr/W. In other embodiments, the combination of two doping elements is Sr/Ta. In other embodiments, the combination of two doping elements is Au/Re. In other embodiments, the combination of two doping elements is Au/Pb. In other embodiments, the combination of two doping elements is Bi/Hf. In other embodiments, the combination of two doping elements is Sr/Sn. In other embodiments, the combination of two doping elements is Mg/N. In other embodiments, the combination of two doping elements is Ca/S. In other embodiments, the combination of two doping elements is Rb/S. In other embodiments, the combination of two doping elements is Sr/Nd. In other embodiments, the combination of two doping elements is Eu/Y. In other embodiments, the combination of two doping elements is Mg/Nd. In other embodiments, the combination of two doping elements is Sr/Na. In other embodiments, the combination of two doping elements is Nd/Mg. In other embodiments, the combination of two doping elements is La/Mg. In other embodiments, the combination of two doping elements is Yb/S. In other embodiments, the combination of two doping elements is Mg/Na. In other embodiments, the combination of two doping elements is Sr/W. In other embodiments, the combination of two doping elements is K/La. In other embodiments, the combination of two doping elements is K/Na. In other embodiments, the combination of two doping elements is Li/Cs. In other embodiments, the combination of two doping elements is Li/Na. In other embodiments, the combination of two doping elements is Zn/K. In other embodiments, the combination of two doping elements is Li/K. In other embodiments, the combination of two doping elements is Rb/Hf. In other embodiments, the combination of two doping elements is Ca/Cs. In other embodiments, the combination of two doping elements is Hf/Bi. In other embodiments, the combination of two doping elements is Sr/Sn. In other embodiments, the combination of two doping elements is Sr/W. In other embodiments, the combination of two doping elements is Sr/Nb. In other embodiments, the combination of two doping elements is Zr/W. In other embodiments, the combination of two doping elements is Y/W. In other embodiments, the combination of two doping elements is Na/W. In other embodiments, the combination of two doping elements is Bi/W. In other embodiments, the combination of two doping elements is Bi/Cs. In other embodiments, the combination of two doping elements is Bi/Ca. In other embodiments, the combination of two doping elements is Bi/Sn. In other embodiments, the combination of two doping elements is Bi/Sb. In other embodiments, the combination of two doping elements is Ge/Hf. In other embodiments, the combination of two doping elements is Hf/Sm. In other embodiments, the combination of two doping elements is Sb/Ag. In other embodiments, the combination of two doping elements is Sb/Bi. In other embodiments, the combination of two doping elements is Sb/Au. In other embodiments, the combination of two doping elements is Sb/Sm. In other embodiments, the combination of two doping elements is Sb/Sr. In other embodiments, the combination of two doping elements is Sb/W. In other embodiments, the combination of two doping elements is Sb/Hf. In other embodiments, the combination of two doping elements is Sb/Yb. In other embodiments, the combination of two doping elements is Sb/Sn. In other embodiments, the combination of two doping elements is Yb/Au. In other embodiments, the combination of two doping elements is Yb/Ta. In other embodiments, the combination of two doping elements is Yb/W. In other embodiments, the combination of two doping elements is Yb/Sr. In other embodiments, the combination of two doping elements is Yb/Pb. In other embodiments, the combination of two doping elements is Yb/W. In other embodiments, the combination of two doping elements is Yb/Ag. In other embodiments, the combination of two doping elements is Au/Sr. In other embodiments, the combination of two doping elements is W/Ge. In other embodiments, the combination of two doping elements is Ta/Hf. In other embodiments, the combination of two doping elements is W/Au. In other embodiments, the combination of two doping elements is Ca/W. In other embodiments, the combination of two doping elements is Au/Re. In other embodiments, the combination of two doping elements is Sm/Li. In other embodiments, the combination of two doping elements is La/K. In other embodiments, the combination of two doping elements is Zn/Cs. In other embodiments, the combination of two doping elements is Zr/Cs. In other embodiments, the combination of two doping elements is Ca/Ce. In other embodiments, the combination of two doping elements is Li/Sr. In other embodiments, the combination of two doping elements is Cs/Zn. In other embodiments, the combination of two doping elements is Dy/K. In other embodiments, the combination of two doping elements is La/Mg. In other embodiments, the combination of two doping elements is In/Sr. In other embodiments, the combination of two doping elements is Sr/Cs. In other embodiments, the combination of two doping elements is Ga/Cs. In other embodiments, the combination of two doping elements is Lu/Fe. In other embodiments, the combination of two doping elements is Sr/Tm. In other embodiments, the combination of two doping elements is La/Dy. In other embodiments, the combination of two doping elements is Mg/K. In other embodiments, the combination of two doping elements is Zr/K. In other embodiments, the combination of two doping elements is Li/Cs. In other embodiments, the combination of two doping elements is Sm/Cs. In other embodiments, the combination of two doping elements is In/K. In other embodiments, the combination of two doping elements is Lu/TI. In other embodiments, the combination of two doping elements is Pr/Zn. In other embodiments, the combination of two doping elements is Lu/Nb. In other embodiments, the combination of two doping elements is Na/Pt. In other embodiments, the combination of two doping elements is Na/Ce. In other embodiments, the combination of two doping elements is Ba/Ta. In other embodiments, the combination of two doping elements is Cu/Sn. In other embodiments, the combination of two doping elements is Ag/Au. In other embodiments, the combination of two doping elements is Al/Bi. In other embodiments, the combination of two doping elements is Al/Mo. In other embodiments, the combination of two doping elements is Al/Nb. In other embodiments, the combination of two doping elements is Au/Pt. In other embodiments, the combination of two doping elements is Ga/Bi. In other embodiments, the combination of two doping elements is Mg/W. In other embodiments, the combination of two doping elements is Pb/Au. In other embodiments, the combination of two doping elements is Sn/Mg. In other embodiments, the combination of two doping elements is Zn/Bi. In other embodiments, the combination of two doping elements is Gd/Ho. In other embodiments, the combination of two doping elements is Zr/Bi. In other embodiments, the combination of two doping elements is Ho/Sr. In other embodiments, the combination of two doping elements is Ca/Sr. In other embodiments, the combination of two doping elements is Sr/Pb. In other embodiments, the combination of two doping elements is Sr/Hf.

In still other embodiments, the nanowire catalysts comprise a rare earth oxide and dopants selected from at least one of the following combinations Mg/La/K, Na/Dy/K, Na/La/Dy, Na/La/Eu, Na/La/K, K/La/S, Li/Cs/La, Li/Sr/Cs, Li/Ga/Cs, Li/Na/Sr, Li/Sm/Cs, Cs/K/La, Sr/Cs/La, Sr/Ho/Tm, La/Nd/S, Li/Rb/Ca, Rb/Sr/Lu, Na/Eu/Hf, Dy/Rb/Gd, Na/Pt/Bi, Ca/Mg/Na, Na/K/Mg, Na/Li/Cs, La/Dy/K, Sm/Li/Sr, Li/Rb/Ga, Li/Cs/Tm, Li/K/La, Ce/Zr/La, Ca/Al/La, Sr/Zn/La, Cs/La/Na, La/S/Sr, Rb/Sr/La, Na/Sr/Lu, Sr/Eu/Dy, La/Dy/Gd, Gd/Li/K, Rb/K/Lu, Na/Ce/Co, Ba/Rh/Ta, Na/Al/Bi, Cs/Eu/S, Sm/Tm/Yb, Hf/Zr/Ta, Na/Ca/Lu, Gd/Ho/Sr, Ca/Sr/W, Na/Zr/Eu/Tm, Sr/W/Li, Ca/Sr/W or Mg/Nd/Fe.

In more embodiments, the nanowire catalysts comprise a rare earth oxide and dopants selected from at least one of the following combinations Nd/Sr/CaO, La/Nd/Sr, La/Bi/Sr, Mg/Nd/Fe, Mg/La/K, Na/Dy/K, Na/La/Dy, Na/La/Eu, Na/La/K, K/La/S, Li/Cs/La, Li/Sr/Cs, Li/Ga/Cs, Li/Na/Sr, Li/Sm/Cs, Cs/K/La, Sr/Cs/La, Sr/Ho/Tm, La/Nd/S, Li/Rb/Ca, Rb/Sr/Lu, Na/Eu/Hf, Dy/Rb/Gd, Na/Pt/Bi, Ca/Mg/Na, Na/K/Mg, Na/Li/Cs, La/Dy/K, Sm/Li/Sr, Li/Rb/Ga, Li/Cs/Tm, Li/K/La, Ce/Zr/La, Ca/Al/La, Sr/Zn/La, Cs/La/Na, La/S/Sr, Rb/Sr/La, Na/Sr/Lu, Sr/Eu/Dy, La/Dy/Gd, Gd/Li/K, Rb/K/Lu, Na/Ce/Co, Ba/Rh/Ta, Na/Al/Bi, Cs/Eu/S, Sm/Tm/Yb, Hf/Zr/Ta, Na/Ca/Lu, Gd/Ho/Sr, Ca/Sr/W, Na/Zr/Eu/Tm, Sr/W/Li or Ca/Sr/W.

In other embodiments of the foregoing rare earth oxide nanowire catalysts, the nanowire catalysts comprise a combination of at least three doping elements. In some embodiments, the combination of at least three different doping elements is Nd/Sr/CaO. In other embodiments, the combination of at least three different doping elements is La/Nd/Sr. In other embodiments, the combination of at least three different doping elements is La/Bi/Sr. In other embodiments, the combination of at least three different doping elements is Mg/Nd/Fe. In other embodiments, the combination of at least three different doping elements is Mg/La/K. In other embodiments, the combination of at least three different doping elements is Na/Dy/K. In other embodiments, the combination of at least three different doping elements is Na/La/Dy. In other embodiments, the combination of at least three different doping elements is Na/La/Eu. In other embodiments, the combination of at least three different doping elements is Na/La/K. In other embodiments, the combination of at least three different doping elements is K/La/S. In other embodiments, the combination of at least three different doping elements is Li/Cs/La. In other embodiments, the combination of at least three different doping elements is Li/Sr/Cs. In other embodiments, the combination of at least three different doping elements is Li/Ga/Cs. In other embodiments, the combination of at least three different doping elements is Li/Na/Sr. In other embodiments, the combination of at least three different doping elements is Li/Sm/Cs. In other embodiments, the combination of at least three different doping elements is Cs/K/La. In other embodiments, the combination of at least three different doping elements is Sr/Cs/La. In other embodiments, the combination of at least three different doping elements is Sr/Ho/Tm. In other embodiments, the combination of at least three different doping elements is La/Nd/S. In other embodiments, the combination of at least three different doping elements is Li/Rb/Ca. In other embodiments, the combination of at least three different doping elements is Rb/Sr/Lu. In other embodiments, the combination of at least three different doping elements is Na/Eu/Hf. In other embodiments, the combination of at least three different doping elements is Dy/Rb/Gd. In other embodiments, the combination of at least three different doping elements is Na/Pt/Bi. In other embodiments, the combination of at least three different doping elements is Ca/Mg/Na. In other embodiments, the combination of at least three different doping elements is Na/K/Mg. In other embodiments, the combination of at least three different doping elements is Na/Li/Cs. In other embodiments, the combination of at least three different doping elements is La/Dy/K. In other embodiments, the combination of at least three different doping elements is Sm/Li/Sr. In other embodiments, the combination of at least three different doping elements is Li/Rb/Ga. In other embodiments, the combination of at least three different doping elements is Li/Cs/Tm. In other embodiments, the combination of at least three different doping elements is Li/K/La. In other embodiments, the combination of at least three different doping elements is Ce/Zr/La. In other embodiments, the combination of at least three different doping elements is Ca/Al/La. In other embodiments, the combination of at least three different doping elements is Sr/Zn/La. In other embodiments, the combination of at least three different doping elements is Cs/La/Na. In other embodiments, the combination of at least three different doping elements is La/S/Sr. In other embodiments, the combination of at least three different doping elements is Rb/Sr/La. In other embodiments, the combination of at least three different doping elements is Na/Sr/Lu. In other embodiments, the combination of at least three different doping elements is Sr/Eu/Dy. In other embodiments, the combination of at least three different doping elements is La/Dy/Gd. In other embodiments, the combination of at least three different doping elements is Gd/Li/K. In other embodiments, the combination of at least three different doping elements is Rb/K/Lu. In other embodiments, the combination of at least three different doping elements is Na/Ce/Co. In other embodiments, the combination of at least three different doping elements is Ba/Rh/Ta. In other embodiments, the combination of at least three different doping elements is Na/Al/Bi. In other embodiments, the combination of at least three different doping elements is Cs/Eu/S. In other embodiments, the combination of at least three different doping elements is Sm/Tm/Yb. In other embodiments, the combination of at least three different doping elements is Hf/Zr/Ta. In other embodiments, the combination of at least three different doping elements is Na/Ca/Lu. In other embodiments, the combination of at least three different doping elements is Gd/Ho/Sr. In other embodiments, the combination of at least three different doping elements is Ca/Sr/W. In other embodiments, the combination of at least three different doping elements is Na/Zr/Eu/Tm. In other embodiments, the combination of at least three different doping elements is Sr/W/Li. In other embodiments, the combination of at least three different doping elements is Ca/Sr/W.

As noted above, certain doping combinations have been found useful in various catalytic reactions, such as OCM. Thus, in one embodiment, the catalytic nanowire comprises a combination of at least four different doping elements, wherein the doping elements are selected from a metal element, a semi-metal element and a non-metal element. For example in certain embodiments the catalytic nanowire comprises a metal oxide, and in other embodiments the catalytic nanowire comprises a lanthanide metal. Still other embodiments provide a catalytic nanowire comprising La₂O₃, Nd₂O₃, Yb₂O₃, Eu₂O₃, Sm₂O₃, Y₂O₃, Ce₂O₃, Pr₂O₃ or combinations thereof. In still other embodiments, the doping elements do not include at least one of Li, B, Na, Co or Ga, and in other embodiments the nanowires do not comprise Mg and/or Mn.

In other embodiments, the catalytic nanowire comprises a lanthanide oxide, for example a lanthanide mixed oxide, for example in some embodiments the catalytic nanowire comprises Ln1_(4-x)Ln2_(x)O₆, wherein Ln1 and Ln2 are each independently a lanthanide element, wherein Ln1 and Ln2 are not the same and x is a number ranging from greater than 0 to less than 4. In other embodiments, the catalytic nanowire comprises La_(4-x)Nd_(x)O₆, wherein x is a number ranging from greater than 0 to less than 4, and in still other embodiments, the catalytic nanowire comprises La₃NdO₆, LaNd₃O₆, La_(1.5)Nd_(2.5)O₆, La_(2.5)Nd_(1.5)O₆, La_(3.2)Nd_(0.8)O₆, La_(3.5)Nd_(0.5)O₆, La_(3.8)Nd_(0.2)O₆ or combinations thereof. In certain other embodiments the mixed oxide comprises Y—La, Zr—La, Pr—La, Ce—La or combinations thereof.

In other embodiments, the doping elements are selected from Eu, Na, Sr, Ca, Mg, Sm, Ho, Tm, W, La, K, Dy, In, Li, Cs, S, Zn, Ga, Rb, Ba, Yb, Ni, Lu, Ta, P, Hf, Tb, Gd, Pt, Bi, Sn, Nb, Sb, Ge, Ag, Au, Pb, B, Re, Fe, Al, Zr, Tl, Pr, Co, Ce, Rh, and Mo. For example, in some embodiments, the combination of at least four different doping elements is: Na/Zr/Eu/Ca, Sr/Sm/Ho/Tm, Na/K/Mg/Tm, Na/La/Eu/In, Na/La/Li/Cs, Li/Cs/La/Tm, Li/Cs/Sr/Tm, Li/Sr/Cs, Li/Sr/Zn/K, Li/K/Sr/La, Li/Na/Rb/Ga, Li/Na/Sr/La, Ba/Sm/Yb/S, Ba/Tm/K/La, Ba/Tm/Zn/K, Cs/La/Tm/Na, Cs/Li/K/La, Sm/Li/Sr/Cs, Sr/Tm/Li/Cs, Zr/Cs/K/La, Rb/Ca/In/Ni, Tm/Lu/Ta/P, Rb/Ca/Dy/P, Mg/La/Yb/Zn, Na/Sr/Lu/Nb, Na/Nd/In/K, Rb/Ga/Tm/Cs, K/La/Zr/Ag, Ho/Cs/Li/La, K/La/Zr/Ag, Na/Sr/Eu/Ca, K/Cs/Sr/La, Na/Mg/TI/P, Sr/La/Dy/S, Na/Ga/Gd/Al, Sm/Tm/Yb/Fe, Rb/Gd/Li/K, Gd/Ho/Al/P, Na/Zr/Eu/Tm Sr/Ho/Tm/Na or Rb/Ga/Tm/Cs or La/Bi/Ce/Nd/Sr.

In other embodiments, the combination of at least four different doping elements is Sr/Sm/Ho/Tm. In other embodiments, the combination of at least four different doping elements is Na/K/Mg/Tm. In other embodiments, the combination of at least four different doping elements is Na/La/Eu/In. In other embodiments, the combination of at least four different doping elements is Na/La/Li/Cs. In other embodiments, the combination of at least four different doping elements is Li/Cs/La/Tm. In other embodiments, the combination of at least four different doping elements is Li/Cs/Sr/Tm. In other embodiments, the combination of at least four different doping elements is Li/Sr/Zn/K. In other embodiments, the combination of at least four different doping elements is Li/Ga/Cs. In other embodiments, the combination of at least four different doping elements is Li/K/Sr/La. In other embodiments, the combination of at least four different doping elements is Li/Na/Rb/Ga. In other embodiments, the combination of at least four different doping elements is Li/Na/Sr/La. In other embodiments, the combination of at least four different doping elements is Ba/Sm/Yb/S. In other embodiments, the combination of at least four different doping elements is Ba/Tm/K/La. In other embodiments, the combination of at least four different doping elements is Ba/Tm/Zn/K. In other embodiments, the combination of at least four different doping elements is Cs/La/Tm/Na. In other embodiments, the combination of at least four different doping elements is Cs/Li/K/La. In other embodiments, the combination of at least four different doping elements is Sm/Li/Sr/Cs. In other embodiments, the combination of at least four different doping elements is Sr/Tm/Li/Cs. In other embodiments, the combination of at least four different doping elements is Zr/Cs/K/La. In other embodiments, the combination of at least four different doping elements is Rb/Ca/In/Ni. In other embodiments, the combination of at least four different doping elements is Tm/Lu/Ta/P. In other embodiments, the combination of at least four different doping elements is Rb/Ca/Dy/P. In other embodiments, the combination of at least four different doping elements is Mg/La/Yb/Zn. In other embodiments, the combination of at least four different doping elements is Na/Sr/Lu/Nb. In other embodiments, the combination of at least four different doping elements is Na/Nd/In/K. In other embodiments, the combination of at least four different doping elements is K/La/Zr/Ag. In other embodiments, the combination of at least four different doping elements is Ho/Cs/Li/La. In other embodiments, the combination of at least four different doping elements is K/La/Zr/Ag. In other embodiments, the combination of at least four different doping elements is Na/Sr/Eu/Ca. In other embodiments, the combination of at least four different doping elements is K/Cs/Sr/La. In other embodiments, the combination of at least four different doping elements is Na/Mg/TI/P. In other embodiments, the combination of at least four different doping elements is Sr/La/Dy/S. In other embodiments, the combination of at least four different doping elements is Na/Ga/Gd/Al. In other embodiments, the combination of at least four different doping elements is Sm/Tm/Yb/Fe. In other embodiments, the combination of at least four different doping elements is Rb/Gd/Li/K. In other embodiments, the combination of at least four different doping elements is Gd/Ho/Al/P. In other embodiments, the combination of at least four different doping elements is Na/Zr/Eu/T. In other embodiments, the combination of at least four different doping elements is Sr/Ho/Tm/Na. In other embodiments, the combination of at least four different doping elements is Na/Zr/Eu/Ca. In other embodiments, the combination of at least four different doping elements is Rb/Ga/Tm/Cs. In other embodiments, the combination of at least four different doping elements is La/Bi/Ce/Nd/Sr.

In other embodiments, the catalytic nanowire comprises at least two different doping elements, wherein the doping elements are selected from a metal element, a semi-metal element and a non-metal element, and wherein at least one of the doping elements is K, Sc, Ti, V, Nb, Ru, Os, Ir, Cd, In, TI, S, Se, Po, Pr, Tb, Dy, Ho, Er, Tm, Lu or an element selected from any of groups 6, 7, 10, 11, 14, 15 or 17. In some embodiments, at least one of the doping elements is K, Ti, V, Nb, Ru, Os, Ir, Cd, In, TI, S, Se, Po, Pr, Tb, Dy, Ho, Er, Tm, Lu or an element selected from any of groups 10, 11, 14, 15 or 17. In certain other embodiments of the foregoing catalytic nanowire, the catalytic nanowire comprises a metal oxide, and in other embodiments the catalytic nanowire comprises a lanthanide metal. In still other embodiments the catalytic nanowire comprises La₂O₃, Nd₂O₃, Yb₂O₃, Eu₂O₃, Sm₂O₃, Y₂O₃, Ce₂O₃, Pr₂O₃ or combinations thereof.

In other embodiments of the foregoing catalytic nanowire, the catalytic nanowire comprises a lanthanide oxide, for example a lanthanide mixed oxide, for example in some embodiments the catalytic nanowire comprises Ln1_(4-x)Ln2_(x)O₆, wherein Ln1 and Ln2 are each independently a lanthanide element, wherein Ln1 and Ln2 are not the same and x is a number ranging from greater than 0 to less than 4. In other embodiments, the catalytic nanowire comprises La_(4-x)Nd_(x)O₆, wherein x is a number ranging from greater than 0 to less than 4, and in still other embodiments, the catalytic nanowire comprises La₃NdO₆, LaNd₃O₆, La_(1.5)Nd_(2.5)O₆, La_(2.5)Nd_(1.5)O₆, La_(3.2)Nd_(0.8)O₆, La_(3.5)Nd_(0.5)O₆, La_(3.8)Nd_(0.2)O₆ or combinations thereof. In certain other embodiments the mixed oxide comprises Y—La, Zr—La, Pr—La, Ce—La or combinations thereof.

In other embodiments of the nanowire comprising at least two doping elements, the doping elements are selected from Eu, Na, Sr, Ca, Mg, Sm, Ho, Tm, W, La, K, Dy, In, Li, Cs, S, Zn, Ga, Rb, Ba, Yb, Ni, Lu, Ta, P, Hf, Tb, Gd, Pt, Bi, Sn, Nb, Sb, Ge, Ag, Au, Pb, B, Re, Fe, Al, Zr, Tl, Pr, Co, Ce, Rh, and Mo.

In yet another aspect, the present disclosure provides a catalytic nanowire comprising at least one of the following dopant combinations: Eu/Na, Sr/Na, Na/Zr/Eu/Ca, Mg/Na, Sr/Sm/Ho/Tm, Sr/W, Mg/La/K, Na/K/Mg/Tm, Na/Dy/K, Na/La/Dy, Sr/Hf/K, Na/La/Eu, Na/La/Eu/In, Na/La/K, Na/La/Li/Cs, K/La, K/La/S, K/Na, Li/Cs, Li/Cs/La, Li/Cs/La/Tm, Li/Cs/Sr/Tm, Li/Sr/Cs, Li/Sr/Zn/K, Li/Ga/Cs, Li/K/Sr/La, Li/Na, Li/Na/Rb/Ga, Li/Na/Sr, Li/Na/Sr/La, Sr/Zr, Li/Sm/Cs, Ba/Sm/Yb/S, Ba/Tm/K/La, Ba/Tm/Zn/K, Sr/Zr/K, Cs/K/La, Cs/La/Tm/Na, Cs/Li/K/La, Sm/Li/Sr/Cs, Sr/Cs/La, Sr/Tm/Li/Cs, Zn/K, Zr/Cs/K/La, Rb/Ca/In/Ni, Sr/Ho/Tm, La/Nd/S, Li/Rb/Ca, Li/K, Tm/Lu/Ta/P, Rb/Ca/Dy/P, Mg/La/Yb/Zn, Rb/Sr/Lu, Na/Sr/Lu/Nb, Na/Eu/Hf, Dy/Rb/Gd, Sr/Ce, Na/Pt/Bi, Rb/Hf, Ca/Cs, Ca/Mg/Na, Hf/Bi, Sr/Sn, Sr/W, Sr/Nb, Sr/Ce/K, Zr/W, Y/W, Na/W, Bi/W, Bi/Cs, Bi/Ca, Bi/Sn, Bi/Sb, Ge/Hf, Hf/Sm, Sb/Ag, Sb/Bi, Sb/Au, Sb/Sm, Sb/Sr, Sb/W, Sb/Hf, Sb/Yb, Sb/Sn, Yb/Au, Yb/Ta, Yb/W, Yb/Sr, Yb/Pb, Yb/W, Yb/Ag, Au/Sr, W/Ge, Sr/Tb, Ta/Hf, W/Au, Ca/W, Au/Re, Sm/Li, La/K, Zn/Cs, Na/K/Mg, Zr/Cs, Ca/Ce, Na/Li/Cs, Li/Sr, Cs/Zn, La/Dy/K, Dy/K, La/Mg, Na/Nd/In/K, In/Sr, Sr/Cs, Rb/Ga/Tm/Cs, Ga/Cs, K/La/Zr/Ag, Lu/Fe, Sr/Tb/K, Sr/Tm, La/Dy, Sm/Li/Sr, Mg/K, Sr/Pr, Li/Rb/Ga, Li/Cs/Tm, Zr/K, Li/Cs, Li/K/La, Ce/Zr/La, Ca/Al/La, Sr/Zn/La, Sr/Cs/Zn, Sm/Cs, In/K, Ho/Cs/Li/La, Sr/Pr/K, Cs/La/Na, La/S/Sr, K/La/Zr/Ag, Lu/TI, Pr/Zn, Rb/Sr/La, Na/Sr/Eu/Ca, K/Cs/Sr/La, Na/Sr/Lu, Sr/Eu/Dy, Lu/Nb, La/Dy/Gd, Na/Mg/TI/P, Na/Pt, Gd/Li/K, Rb/K/Lu, Sr/La/Dy/S, Na/Ce/Co, Na/Ce, Na/Ga/Gd/Al, Ba/Rh/Ta, Ba/Ta, Na/Al/Bi, Sr/Hf/Rb, Cs/Eu/S, Sm/Tm/Yb/Fe, Sm/Tm/Yb, Hf/Zr/Ta, Rb/Gd/Li/K, Gd/Ho/Al/P, Na/Ca/Lu, Cu/Sn, Ag/Au, Al/Bi, Al/Mo, Al/Nb, Au/Pt, Ga/Bi, Mg/W, Pb/Au, Sn/Mg, Sr/B, Zn/Bi, Gd/Ho, Zr/Bi, Ho/Sr, Gd/Ho/Sr, Ca/Sr, Ca/Sr/W, Sr/Ho/Tm/Na, Na/Zr/Eu/Tm, Sr/Ho/Tm/Na, Sr/Pb, Sr/W/Li, Ca/Sr/W or Sr/Hf.

In other embodiments of the foregoing catalytic nanowire, the dopant is selected from Cs/Eu/S, Sm/Tm/Yb/Fe, Sm/Tm/Yb, Hf/Zr/Ta, Rb/Gd/Li/K, Gd/Ho/Al/P, Na/Ca/Lu, Cu/Sn, Ag/Au, Al/Bi, Al/Mo, Al/Nb, Au/Pt, Ga/Bi, Mg/W, Pb/Au, Sn/Mg, Zn/Bi, Gd/Ho, Zr/Bi, Ho/Sr, Gd/Ho/Sr, Ca/Sr, Ca/Sr/W, Na/Zr/Eu/Tm, Sr/Ho/Tm/Na, Sr/Pb, Ca, Sr/W/Li, Ca/Sr/W, Sr/Hf, Eu/Na, Sr/Na, Na/Zr/Eu/Ca, Mg/Na, Sr/Sm/Ho/Tm, Sr/W, Mg/La/K, Na/K/Mg/Tm, Na/Dy/K, Na/La/Dy, Na/La/Eu, Na/La/Eu/In, Na/La/K, Na/La/Li/Cs, K/La, K/La/S, K/Na, Li/Cs, Li/Cs/La, Li/Cs/La/Tm, Li/Cs/Sr/Tm, Li/Sr/Cs, Li/Sr/Zn/K, Li/Ga/Cs, Li/K/Sr/La, Li/Na, Li/Na/Rb/Ga and Li/Na/Sr.

In still other embodiments of the foregoing catalytic nanowire the dopant is selected from Li/Na/Sr/La, Li/Sm/Cs, Ba/Sm/Yb/S, Ba/Tm/K/La, Ba/Tm/Zn/K, Cs/K/La, Cs/La/Tm/Na, Cs/Li/K/La, Sm/Li/Sr/Cs, Sr/Cs/La, Sr/Tm/Li/Cs, Zn/K, Zr/Cs/K/La, Rb/Ca/In/Ni, Sr/Ho/Tm, La/Nd/S, Li/Rb/Ca, Li/K, Tm/Lu/Ta/P, Rb/Ca/Dy/P, Mg/La/Yb/Zn, Rb/Sr/Lu, Na/Sr/Lu/Nb, Na/Eu/Hf, Dy/Rb/Gd, Na/Pt/Bi, Rb/Hf, Ga/Cs, K/La/Zr/Ag, Lu/Fe, Sr/Tm, La/Dy, Sm/Li/Sr, Mg/K, Li/Rb/Ga, Li/Cs/Tm, Zr/K, Li/Cs, Li/K/La, Ce/Zr/La, Ca/Al/La, Sr/Zn/La, Sr/Cs/Zn, Sm/Cs, In/K, Ho/Cs/Li/La, Cs/La/Na, La/S/Sr, K/La/Zr/Ag, Lu/TI, Pr/Zn, Rb/Sr/La, Na/Sr/Eu/Ca, K/Cs/Sr/La, Na/Sr/Lu, Sr/Eu/Dy, Lu/Nb, La/Dy/Gd, Na/Mg/TI/P, Na/Pt, Gd/Li/K, Rb/K/Lu, Sr/La/Dy/S, Na/Ce/Co, Na/Ce, Na/Ga/Gd/Al, Ba/Rh/Ta, Ba/Ta, Na/Al/Bi, Cs/Eu/S, Sm/Tm/Yb/Fe, Sm/Tm/Yb, Hf/Zr/Ta, Rb/Gd/Li/K, Gd/Ho/Al/P and Na/Ca/Lu.

In still other embodiments of the foregoing catalytic nanowire, the dopant is selected from Ta/Hf, W/Au, Ca/W, Au/Re, Sm/Li, La/K, Zn/Cs, Na/K/Mg, Zr/Cs, Ca/Ce, Na/Li/Cs, Li/Sr, Cs/Zn, La/Dy/K, Dy/K, La/Mg, Na/Nd/In/K, In/Sr, Sr/Cs, Rb/Ga/Tm/Cs, Ga/Cs, K/La/Zr/Ag, Lu/Fe, Sr/Tm, La/Dy, Sm/Li/Sr, Mg/K, Li/Rb/Ga, Li/Cs/Tm, Zr/K, Li/Cs, Li/K/La, Ce/Zr/La, Ca/Al/La, Sr/Zn/La, Sr/Cs/Zn, Sm/Cs, In/K, Ho/Cs/Li/La, Cs/La/Na, La/S/Sr, K/La/Zr/Ag, Lu/TI, Pr/Zn, Rb/Sr/La, Na/Sr/Eu/Ca, K/Cs/Sr/La, Na/Sr/Lu, Sr/Eu/Dy, Lu/Nb, La/Dy/Gd, Na/Mg/TI/P, Na/Pt, Gd/Li/K, Li/Sr/Cs, Li/Sr/Zn/K, Li/Ga/Cs, Li/K/Sr/La, Li/Na, Li/Na/Rb/Ga, Li/Na/Sr, Li/Na/Sr/La, Li/Sm/Cs, Ba/Sm/Yb/S, Ba/Tm/K/La, Ba/Tm/Zn/K, Cs/K/La, Cs/La/Tm/Na, Cs/Li/K/La, Sm/Li/Sr/Cs, Sr/Cs/La, Sr/Tm/Li/Cs, Zn/K, Zr/Cs/K/La, Rb/Ca/In/Ni, Sr/Ho/Tm, La/Nd/S, Li/Rb/Ca, Li/K, Tm/Lu/Ta/P, Rb/Ca/Dy/P, Mg/La/Yb/Zn, Rb/Sr/Lu, Na/Sr/Lu/Nb, Na/Eu/Hf, Dy/Rb/Gd, Na/Pt/Bi, Rb/Hf, Ca/Cs, Ca/Mg/Na, Hf/Bi, Sr/Sn, Sr/W, Sr/Nb, Zr/W, Y/W, Na/W, Bi/W, Bi/Cs, Bi/Ca, Bi/Sn, Bi/Sb, Ge/Hf, Hf/Sm, Sb/Ag, Sb/Bi, Sb/Au, Sb/Sm, Sb/Sr, Sb/W, Sb/Hf, Sb/Yb, Sb/Sn, Yb/Au, Yb/Ta, Yb/W, Yb/Sr, Yb/Pb, Yb/W, Yb/Ag, Au/Sr and W/Ge.

For example in certain embodiments of the foregoing catalytic nanowire, the catalytic nanowire comprises a metal oxide, and in other embodiments the catalytic nanowire comprises a lanthanide metal. In still other embodiments, the catalytic nanowire comprises La₂O₃, Nd₂O₃, Yb₂O₃, Eu₂O₃, Sm₂O₃, Y₂O₃, Ce₂O₃, Pr₂O₃ or combinations thereof.

In other embodiments of the foregoing nanowire, the catalytic nanowire comprises a lanthanide oxide, for example a lanthanide mixed oxide, for example in some embodiments the catalytic nanowire comprises Ln1_(4-x)Ln2_(x)O₆, wherein Ln1 and Ln2 are each independently a lanthanide element, wherein Ln1 and Ln2 are not the same and x is a number ranging from greater than 0 to less than 4. In other embodiments, the catalytic nanowire comprises La_(4-x)Nd_(x)O₆, wherein x is a number ranging from greater than 0 to less than 4, and in still other embodiments, the catalytic nanowire comprises La₃NdO₆, LaNd₃O₆, La_(1.5)Nd_(2.5)O₆, La_(2.5)Nd_(1.5)O₆, La_(3.2)Nd_(0.8)O₆, La_(3.5)Nd_(0.5)O₆, La_(3.8)Nd_(0.2)O₆ or combinations thereof. In certain other embodiments the mixed oxide comprises Y—La, Zr—La, Pr—La, Ce—La or combinations thereof.

In still other embodiments, the disclosure provides a catalytic nanowire comprising Ln1_(4-x)Ln2_(x)O₆ and a dopant comprising a metal element, a semi-metal element, a non-metal element or combinations thereof, wherein Ln1 and Ln2 are each independently a lanthanide element, wherein Ln1 and Ln2 are not the same and x is a number ranging from greater than 0 to less than 4. For example, in certain embodiments the catalytic nanowire comprises La_(4-x)Ln1_(x)O₆, wherein Ln1 is a lanthanide element and x is a number ranging from greater than 0 to less than 4, and in other specific embodiments, the catalytic nanowire comprises La_(4-x)Nd_(x)O₆, wherein x is a number ranging from greater than 0 to less than 4.

Still further embodiments of the foregoing nanowire include embodiments wherein the catalytic nanowire comprises comprises La₃NdO₆, LaNd₃O₆, La_(1.5)Nd_(2.5)O₆, La_(2.5)Nd_(1.5)O₆, La_(3.2)Nd_(0.8)O₆, La_(3.5)Nd_(0.5)O₆, La_(3.8)Nd_(0.2)O₆ or combinations thereof.

In other embodiments, the dopant is selected from: Eu, Na, Sr, Ca, Mg, Sm, Ho, Tm, W, La, K, Dy, In, Li, Cs, S, Zn, Ga, Rb, Ba, Yb, Ni, Lu, Ta, P, Hf, Tb, Gd, Pt, Bi, Sn, Nb, Sb, Ge, Ag, Au, Pb, B, Re, Fe, Al, Zr, Tl, Pr, Co, Ce, Rh, and Mo. For example in certain embodiments, the catalytic nanowire comprises at least one of the following dopant combinations: Eu/Na, Sr/Na, Na/Zr/Eu/Ca, Mg/Na, Sr/Sm/Ho/Tm, Sr/W, Mg/La/K, Na/K/Mg/Tm, Na/Dy/K, Na/La/Dy, Sr/Hf/K, Na/La/Eu, Na/La/Eu/In, Na/La/K, Na/La/Li/Cs, K/La, K/La/S, K/Na, Li/Cs, Li/Cs/La, Li/Cs/La/Tm, Li/Cs/Sr/Tm, Li/Sr/Cs, Li/Sr/Zn/K, Li/Ga/Cs, Li/K/Sr/La, Li/Na, Li/Na/Rb/Ga, Li/Na/Sr, Li/Na/Sr/La, Sr/Zr, Li/Sm/Cs, Ba/Sm/Yb/S, Ba/Tm/K/La, Ba/Tm/Zn/K, Sr/Zr/K, Cs/K/La, Cs/La/Tm/Na, Cs/Li/K/La, Sm/Li/Sr/Cs, Sr/Cs/La, Sr/Tm/Li/Cs, Zn/K, Zr/Cs/K/La, Rb/Ca/In/Ni, Sr/Ho/Tm, La/Nd/S, Li/Rb/Ca, Li/K, Tm/Lu/Ta/P, Rb/Ca/Dy/P, Mg/La/Yb/Zn, Rb/Sr/Lu, Na/Sr/Lu/Nb, Na/Eu/Hf, Dy/Rb/Gd, Sr/Ce, Na/Pt/Bi, Rb/Hf, Ca/Cs, Ca/Mg/Na, Hf/Bi, Sr/Sn, Sr/W, Sr/Nb, Sr/Ce/K, Zr/W, Y/W, Na/W, Bi/W, Bi/Cs, Bi/Ca, Bi/Sn, Bi/Sb, Ge/Hf, Hf/Sm, Sb/Ag, Sb/Bi, Sb/Au, Sb/Sm, Sb/Sr, Sb/W, Sb/Hf, Sb/Yb, Sb/Sn, Yb/Au, Yb/Ta, Yb/W, Yb/Sr, Yb/Pb, Yb/W, Yb/Ag, Au/Sr, W/Ge, Sr/Tb, Ta/Hf, W/Au, Ca/W, Au/Re, Sm/Li, La/K, Zn/Cs, Na/K/Mg, Zr/Cs, Ca/Ce, Na/Li/Cs, Li/Sr, Cs/Zn, La/Dy/K, Dy/K, La/Mg, Na/Nd/In/K, In/Sr, Sr/Cs, Rb/Ga/Tm/Cs, Ga/Cs, K/La/Zr/Ag, Lu/Fe, Sr/Tb/K, Sr/Tm, La/Dy, Sm/Li/Sr, Mg/K, Sr/Pr, Li/Rb/Ga, Li/Cs/Tm, Zr/K, Li/Cs, Li/K/La, Ce/Zr/La, Ca/Al/La, Sr/Zn/La, Sr/Cs/Zn, Sm/Cs, In/K, Ho/Cs/Li/La, Sr/Pr/K, Cs/La/Na, La/S/Sr, K/La/Zr/Ag, Lu/TI, Pr/Zn, Rb/Sr/La, Na/Sr/Eu/Ca, K/Cs/Sr/La, Na/Sr/Lu, Sr/Eu/Dy, Lu/Nb, La/Dy/Gd, Na/Mg/TI/P, Na/Pt, Gd/Li/K, Rb/K/Lu, Sr/La/Dy/S, Na/Ce/Co, Na/Ce, Na/Ga/Gd/Al, Ba/Rh/Ta, Ba/Ta, Na/Al/Bi, Sr/Hf/Rb, Cs/Eu/S, Sm/Tm/Yb/Fe, Sm/Tm/Yb, Hf/Zr/Ta, Rb/Gd/Li/K, Gd/Ho/Al/P, Na/Ca/Lu, Cu/Sn, Ag/Au, Al/Bi, Al/Mo, Al/Nb, Au/Pt, Ga/Bi, Mg/W, Pb/Au, Sn/Mg, Sr/B, Zn/Bi, Gd/Ho, Zr/Bi, Ho/Sr, Gd/Ho/Sr, Ca/Sr, Ca/Sr/W, Sr/Ho/Tm/Na, Na/Zr/Eu/Tm, Sr/Ho/Tm/Na, Sr/Pb, Sr/W/Li, Ca/Sr/W or Sr/Hf.

In other embodiments, the disclosure provides a nanowire comprising a mixed oxide of Y—La, Zr—La, Pr—La, Ce—La or combinations thereof and at least one dopant selected from a metal element, a semi-metal element and a non-metal element. For example, in some embodiments the at least one dopant is selected from Eu, Na, Sr, Ca, Mg, Sm, Ho, Tm, W, La, K, Dy, In, Li, Cs, S, Zn, Ga, Rb, Ba, Yb, Ni, Lu, Ta, P, Hf, Tb, Gd, Pt, Bi, Sn, Nb, Sb, Ge, Ag, Au, Pb, B, Re, Fe, Al, Zr, Tl, Pr, Co, Ce, Rh, and Mo, and in even other embodiments, the catalytic nanowire comprises at least one of the following dopant combinations: Eu/Na, Sr/Na, Na/Zr/Eu/Ca, Mg/Na, Sr/Sm/Ho/Tm, Sr/W, Mg/La/K, Na/K/Mg/Tm, Na/Dy/K, Na/La/Dy, Sr/Hf/K, Na/La/Eu, Na/La/Eu/In, Na/La/K, Na/La/Li/Cs, K/La, K/La/S, K/Na, Li/Cs, Li/Cs/La, Li/Cs/La/Tm, Li/Cs/Sr/Tm, Li/Sr/Cs, Li/Sr/Zn/K, Li/Ga/Cs, Li/K/Sr/La, Li/Na, Li/Na/Rb/Ga, Li/Na/Sr, Li/Na/Sr/La, Sr/Zr, Li/Sm/Cs, Ba/Sm/Yb/S, Ba/Tm/K/La, Ba/Tm/Zn/K, Sr/Zr/K, Cs/K/La, Cs/La/Tm/Na, Cs/Li/K/La, Sm/Li/Sr/Cs, Sr/Cs/La, Sr/Tm/Li/Cs, Zn/K, Zr/Cs/K/La, Rb/Ca/In/Ni, Sr/Ho/Tm, La/Nd/S, Li/Rb/Ca, Li/K, Tm/Lu/Ta/P, Rb/Ca/Dy/P, Mg/La/Yb/Zn, Rb/Sr/Lu, Na/Sr/Lu/Nb, Na/Eu/Hf, Dy/Rb/Gd, Sr/Ce, Na/Pt/Bi, Rb/Hf, Ca/Cs, Ca/Mg/Na, Hf/Bi, Sr/Sn, Sr/W, Sr/Nb, Sr/Ce/K, Zr/W, Y/W, Na/W, Bi/W, Bi/Cs, Bi/Ca, Bi/Sn, Bi/Sb, Ge/Hf, Hf/Sm, Sb/Ag, Sb/Bi, Sb/Au, Sb/Sm, Sb/Sr, Sb/W, Sb/Hf, Sb/Yb, Sb/Sn, Yb/Au, Yb/Ta, Yb/W, Yb/Sr, Yb/Pb, Yb/W, Yb/Ag, Au/Sr, W/Ge, Sr/Tb, Ta/Hf, W/Au, Ca/W, Au/Re, Sm/Li, La/K, Zn/Cs, Na/K/Mg, Zr/Cs, Ca/Ce, Na/Li/Cs, Li/Sr, Cs/Zn, La/Dy/K, Dy/K, La/Mg, Na/Nd/In/K, In/Sr, Sr/Cs, Rb/Ga/Tm/Cs, Ga/Cs, K/La/Zr/Ag, Lu/Fe, Sr/Tb/K, Sr/Tm, La/Dy, Sm/Li/Sr, Mg/K, Sr/Pr, Li/Rb/Ga, Li/Cs/Tm, Zr/K, Li/Cs, Li/K/La, Ce/Zr/La, Ca/Al/La, Sr/Zn/La, Sr/Cs/Zn, Sm/Cs, In/K, Ho/Cs/Li/La, Sr/Pr/K, Cs/La/Na, La/S/Sr, K/La/Zr/Ag, Lu/TI, Pr/Zn, Rb/Sr/La, Na/Sr/Eu/Ca, K/Cs/Sr/La, Na/Sr/Lu, Sr/Eu/Dy, Lu/Nb, La/Dy/Gd, Na/Mg/TI/P, Na/Pt, Gd/Li/K, Rb/K/Lu, Sr/La/Dy/S, Na/Ce/Co, Na/Ce, Na/Ga/Gd/Al, Ba/Rh/Ta, Ba/Ta, Na/Al/Bi, Sr/Hf/Rb, Cs/Eu/S, Sm/Tm/Yb/Fe, Sm/Tm/Yb, Hf/Zr/Ta, Rb/Gd/Li/K, Gd/Ho/Al/P, Na/Ca/Lu, Cu/Sn, Ag/Au, Al/Bi, Al/Mo, Al/Nb, Au/Pt, Ga/Bi, Mg/W, Pb/Au, Sn/Mg, Sr/B, Zn/Bi, Gd/Ho, Zr/Bi, Ho/Sr, Gd/Ho/Sr, Ca/Sr, Ca/Sr/W, Sr/Ho/Tm/Na, Na/Zr/Eu/Tm, Sr/Ho/Tm/Na, Sr/Pb, Sr/W/Li, Ca/Sr/W or Sr/Hf.

In still other embodiments, the invention provides a catalytic nanowire comprising a mixed oxide of a rare earth element and a Group 13 element, wherein the catalytic nanowire further comprises one or more Group 2 elements. In some embodiments, the Group 13 element is B, Al, Ga or In. In other embodiments, the Group 2 element is Ca or Sr. In still other embodiments, the rare earth element is La, Y, Nd, Yb, Sm, Pr, Ce or Eu.

Examples of the foregoing catalytic nanowires include catalytic nanowires comprising CaLnBO_(x), CaLnAlO_(x), CaLnGaO_(x), CaLnInO_(x), CaLnAlSrO_(x) and CaLnAlSrO_(x), wherein Ln is a lanthanide or yttrium and x is number such that all charges are balanced. For example, in some embodiments, the catalytic nanowire comprises CaLaBO₄, CaLaAlO₄, CaLaGaO₄, CaLaInO₄, CaLaAlSrO₅, CaLaAlSrO₅, CaNdBO₄, CaNdAlO₄, CaNdGaO₄, CaNdInO₄, CaNdAlSrO₄, CaNdAlSrO₄, CaYbBO₄, CaYbAlO₄, CaYbGaO₄, CaYbInO₄, CaYbAlSrO₅, CaYbAlSrO₅, CaEuBO₄, CaEuAlO₄, CaEuGaO₄, CaEuInO₄, CaEuAlSrO₅, CaEuAlSrO₅, CaSmBO₄, CaSmAlO₄, CaSmGaO₄, CaSmInO₄, CaSmAlSrO₅, CaSmAlSrO₅, CaYBO₄, CaYAlO₄, CaYGaO₄, CaYInO₄, CaYAlSrOs₅, CaYAlSrO₅, CaCeBO₄, CaCeAlO₄, CaCeGaO₄, CaCeInO₄, CaCeAlSrO₅, CaCeAlSrO₅, CaPrBO₄, CaPrAlO₄, CaPrGaO₄, CaPrInO₄, CaPrAlSrO₅ or CaPrAlSrO₅.

In still other embodiments, the invention is directed to a catalytic nanowire comprising a rare earth oxide, wherein the nanowires are doped with a dopant (or dopants) selected from Eu/Na, Sr/Na, Na/Zr/Eu/Ca, Mg/Na, Sr/Sm/Ho/Tm, Sr/W, Mg/La/K, Na/K/Mg/Tm, Na/Dy/K, Na/La/Dy, Na/La/Eu, Na/La/Eu/In, Na/La/K, Na/La/Li/Cs, K/La, K/La/S, K/Na, Li/Cs, Li/Cs/La, Li/Cs/La/Tm, Li/Cs/Sr/Tm, Li/Sr/Cs, Li/Sr/Zn/K, Li/Ga/Cs, Li/K/Sr/La, Li/Na, Li/Na/Rb/Ga, Li/Na/Sr, Li/Na/Sr/La, Li/Sm/Cs, Ba/Sm/Yb/S, Ba/Tm/K/La, Ba/Tm/Zn/K, Cs/K/La, Cs/La/Tm/Na, Cs/Li/K/La, Sm/Li/Sr/Cs, Sr/Cs/La, Sr/Tm/Li/Cs, Zn/K, Zr/Cs/K/La, Rb/Ca/In/Ni, Sr/Ho/Tm, La/Nd/S, Li/Rb/Ca, Li/K, Tm/Lu/Ta/P, Rb/Ca/Dy/P, Mg/La/Yb/Zn, Rb/Sr/Lu, Na/Sr/Lu/Nb, Na/Eu/Hf, Dy/Rb/Gd, Na/Pt/Bi, Rb/Hf, Ca/Cs, Ca/Mg/Na, Hf/Bi, Sr/Sn, Sr/W, Sr/Nb, Zr/W, Y/W, Na/W, Bi/W, Bi/Cs, Bi/Ca, Bi/Sn, Bi/Sb, Ge/Hf, Hf/Sm, Sb/Ag, Sb/Bi, Sb/Au, Sb/Sm, Sb/Sr, Sb/W, Sb/Hf, Sb/Yb, Sb/Sn, Yb/Au, Yb/Ta, Yb/W, Yb/Sr, Yb/Pb, Yb/W, Yb/Ag, Au/Sr, W/Ge, Ta/Hf, W/Au, Ca/W, Au/Re, Sm/Li, La/K, Zn/Cs, Na/K/Mg, Zr/Cs, Ca/Ce, Na/Li/Cs, Li/Sr, Cs/Zn, La/Dy/K, Dy/K, La/Mg, Na/Nd/In/K, In/Sr, Sr/Cs, Rb/Ga/Tm/Cs, Ga/Cs, K/La/Zr/Ag, Lu/Fe, Sr/Tm, La/Dy, Sm/Li/Sr, Mg/K, Li/Rb/Ga, Li/Cs/Tm, Zr/K, Li/Cs, Li/K/La, Ce/Zr/La, Ca/Al/La, Sr/Zn/La, Sr/Cs/Zn, Sm/Cs, In/K, Ho/Cs/Li/La, Cs/La/Na, La/S/Sr, K/La/Zr/Ag, Lu/TI, Pr/Zn, Rb/Sr/La, Na/Sr/Eu/Ca, K/Cs/Sr/La, Na/Sr/Lu, Sr/Eu/Dy, Lu/Nb, La/Dy/Gd, Na/Mg/TI/P, Na/Pt, Gd/Li/K, Rb/K/Lu, Sr/La/Dy/S, Na/Ce/Co, Na/Ce, Na/Ga/Gd/Al, Ba/Rh/Ta, Ba/Ta, Na/Al/Bi, Cs/Eu/S, Sm/Tm/Yb/Fe, Sm/Tm/Yb, Hf/Zr/Ta, Rb/Gd/Li/K, Gd/Ho/Al/P, Na/Ca/Lu, Cu/Sn, Ag/Au, Al/Bi, Al/Mo, Al/Nb, Au/Pt, Ga/Bi, Mg/W, Pb/Au, Sn/Mg, Zn/Bi, Gd/Ho, Zr/Bi, Ho/Sr, Gd/Ho/Sr, Ca/Sr, Ca/Sr/W, Sr/Ho/Tm/Na, Na/Zr/Eu/Tm, Sr/Pb, Sr/W/Li, Ca/Sr/W or Sr/Hf. In one embodiment of the foregoing, nanowires comprise La₂O₃, Nd₂O₃, Yb₂O₃, Eu₂O₃, Sm₂O₃, Ln1_(4-x)Ln2_(x)O₆, La_(4-x)Ln1_(x)O₆, La_(4-x)Nd_(x)O₆, wherein Ln1 and Ln2 are each independently a lanthanide element, wherein Ln1 and Ln2 are not the same and x is a number ranging from greater than 0 to less than 4, La₃NdO₆, LaNd₃O₆, La_(1.5)Nd_(2.5)O₆, La_(2.5)Nd_(1.5)O₆, La_(3.2)Nd_(0.8)O₆, La_(3.5)Nd_(0.5)O₆, La_(3.8)Nd_(0.2)O₆, Y—La, Zr—La, Pr—La or Ce—La or combinations thereof.

In other embodiments, the nanowires comprise La₂O₃, Yb₂O₃, Eu₂O₃, Sm₂O₃, Y₂O₃, Ce₂O₃, Pr₂O₃, Ln1_(4-x)Ln2_(x)O₆, La_(4-x)Ln1_(x)O₆, La_(4-x)Nd_(x)O₆, wherein Ln11 and Ln2 are each independently a lanthanide element, wherein Ln1 and Ln2 are not the same and x is a number ranging from greater than 0 to less than 4, La₃NdO₆, LaNd₃O₆, La_(1.5)Nd_(2.5)O₆, La_(2.5)Nd_(1.5)O₆, La_(3.2)Nd_(0.8)O₆, La_(3.5)Nd_(0.5)O₆, La_(3.8)Nd_(0.2)O₆, Y—La, Zr—La, Pr—La or Ce—La doped with Sr/Ta, for example in some embodiments the nanowires comprise Sr/Ta/La₂O₃, Sr/Ta/Yb₂O₃, Sr/Ta/Eu₂O₃, Sr/Ta/Sm₂O₃, Sr/Ta/La₃NdO₆, Sr/Ta/LaNd₃O₆, Sr/Ta/La_(1.5)Nd_(2.5)O₆, Sr/Ta/La_(2.5)Nd_(1.5)O₆, Sr/Ta/La_(3.2)Nd_(0.8)O₆, Sr/Ta/La_(3.5)Nd_(0.5)O₆, Sr/Ta/La_(3.8)Nd_(0.2)O₆, Sr/Ta/Y—La, Sr/Ta/Zr—La, Sr/Ta/Pr—La or Sr/Ta/Ce—La or combinations thereof. In other embodiments, the nanowires comprise Ln1_(4-x)Ln2_(x)O₆, La_(4-x)Ln1_(x)O₆, La_(4-x)Nd_(x)O₆, wherein Ln1 and Ln2 are each independently a lanthanide element, wherein Ln1 and Ln2 are not the same and x is a number ranging from greater than 0 to less than 4, La₃NdO₆, LaNd₃O₆, La_(1.5)Nd_(2.5)O₆, La_(2.5)Nd_(1.5)O₆, La_(3.2)Nd_(0.8)O₆, La_(3.5)Nd_(0.5)O₆, La_(3.8)Nd_(0.2)O₆, Y—La, Zr—La, Pr—La or Ce—La doped with Na, Sr, Ca, Yb, Cs or Sb, for example the nanowires may comprise Na/Ln1_(4-x)Ln2_(x)O₆, Sr/Ln1_(4-x)Ln2_(x)O₆, Ca/Ln1_(4-x)Ln2_(x)O₆, Yb/Ln1_(4-x)Ln2_(x)O₆, Cs/Ln1_(4-x)Ln2_(x)O₆, Sb/Ln1_(4-x)Ln2_(x)O₆, Na/La_(4-x)Ln_(1x)O₆, Na/La₃NdO₆, Sr/La_(4-x)Ln1_(x)O₆, Ca/La_(4-x)Ln1_(x)O₆, Yb/La_(4-x)Ln1_(x)O₆, Cs/La_(4-x)Ln1_(x)O₆, Sb/La_(4-x)Ln1_(x)O₆, Na/La_(4-x)Nd_(x)O₆, Sr/La_(4-x)Nd_(x)O₆, Ca/La_(4-x)Nd_(x)O₆, Yb/La_(4-x)Nd_(x)O₆, Cs La_(4-x)Nd_(x)O₆, Sb/La_(4-x)Nd_(x)O₆, Na/LaNd₃O₆, Na/La_(1.5)Nd_(2.5)O₆, Na/La_(2.5)Nd_(1.5)O₆, Na/La_(3.2)Nd_(0.8)O₆, Na/La_(3.5)Nd_(0.5)O₆, Na/La_(3.8)Nd_(0.2)O₆, Na/Y—La, Na/Zr—La, Na/Pr—La, Na/Ce—La, Sr/La₃NdO₆, Sr/LaNd₃O₆, Sr/La_(1.5)Nd_(2.5)O₆, Sr/La_(2.5)Nd_(1.5)O₆, Sr/La_(3.2)Nd_(0.8)O₆, Sr/La_(3.5)Nd_(0.5)O₆, Sr/La_(3.8)Nd_(0.2)O₆, Sr/Y—La, Sr/Zr—La, Sr/Pr—La, Sr/Ce—La, Ca/La₃NdO₆, Ca/LaNd₃O₆, Ca/La_(1.5)Nd_(2.5)O₆, Ca/La_(2.5)Nd_(1.5)O₆, Ca/La_(3.2)Nd_(0.8)O₆, Ca/La_(3.5)Nd_(0.5)O₆, Ca/La_(3.8)Nd_(0.2)O₆, Ca/Y—La, Ca/Zr—La, Ca/Pr—La, Ca/Ce—La, Yb/La₃NdO₆, Yb/LaNd₃O₆, Yb/La_(1.5)Nd_(2.5)O₆, Yb/La_(2.5)Nd_(1.5)O₆, Yb/La_(3.2)Nd_(0.8)O₆, Yb/La_(3.5)Nd_(0.5)O₆, Yb/La_(3.8)Nd_(0.2)O₆, Yb/Y—La, Yb/Zr—La, Yb/Pr—La, Yb/Ce—La, Cs/La₃NdO₆ LaNd₃O₆, Cs/La_(1.5)Nd_(2.5)O₆, Cs/La_(2.5)Nd_(1.5)O₆, Cs/La_(3.2)Nd_(0.8)O₆, Cs/La_(3.5)Nd_(0.5)O₆, Cs/La_(3.8)Nd_(0.2)O₆, Cs/Y—La, Cs/Zr—La, Cs/Pr—La, Cs/Ce—La, Sb/La₃NdO₆, Sb/LaNd₃O₆, Sb/La_(1.5)Nd_(2.5)O₆, Sb/La_(2.5)Nd_(1.5)O₆, Sb/La_(3.2)Nd_(0.8)O₆, Sb/La_(3.5)Nd_(0.5)O₆, Sb/La_(3.8)Nd_(0.2)O₆, Sb/Y—La, Sb/Zr—La, Sb/Pr—La, Sb/Ce—La or combinations thereof.

Furthermore, the present inventors have discovered that lanthanide oxides doped with alkali metals and/or alkaline earth metals and at least one other dopant selected from Groups 3-16 have desirable catalytic properties and are useful in a variety of catalytic reactions, such as OCM. Accordingly, in one embodiment the nanowire catalysts comprise a lanthanide oxide doped with an alkali metal, an alkaline earth metal or combinations thereof, and at least one other dopant from groups 3-16. In some embodiments, the nanowire catalyst comprises a lanthanide oxide, an alkali metal dopant and at least one other dopant selected from Groups 3-16. In other embodiments, the nanowire catalyst comprises a lanthanide oxide, an alkaline earth metal dopant and at least one other dopant selected from Groups 3-16.

In some more specific embodiments of the foregoing, the nanowire catalyst comprises a lanthanide oxide, a lithium dopant and at least one other dopant selected from Groups 3-16. In still other embodiments, the nanowire catalyst comprises a lanthanide oxide, a sodium dopant and at least one other dopant selected from Groups 3-16. In other embodiments, the nanowire catalyst comprises a lanthanide oxide, a potassium dopant and at least one other dopant selected from Groups 3-16. In other embodiments, the nanowire catalyst comprises a lanthanide oxide, a rubidium dopant and at least one other dopant selected from Groups 3-16. In more embodiments, the nanowire catalyst comprises a lanthanide oxide, a caesium dopant and at least one other dopant selected from Groups 3-16.

In still other embodiments of the foregoing, the nanowire catalyst comprises a lanthanide oxide, a beryllium dopant and at least one other dopant selected from Groups 3-16. In other embodiments, the nanowire catalyst comprises a lanthanide oxide, a magnesium dopant and at least one other dopant selected from Groups 3-16. In still other embodiments, the nanowire catalyst comprises a lanthanide oxide, a calcium dopant and at least one other dopant selected from Groups 3-16. In more embodiments, the nanowire catalyst comprises a lanthanide oxide, a strontium dopant and at least one other dopant selected from Groups 3-16. In more embodiments, the nanowire catalyst comprises a lanthanide oxide, a barium dopant and at least one other dopant selected from Groups 3-16.

In some embodiments of the foregoing lanthanide oxide nanowire catalysts, the catalysts comprise La₂O₃, Nd₂O₃, Yb₂O₃, Eu₂O₃, Sm₂O₃, Ln1_(4-x)Ln2_(x)O₆, La_(4-x)Ln1_(x)O₆, La_(4-x)Nd_(x)O₆, wherein Ln1 and Ln2 are each independently a lanthanide element, wherein Ln1 and Ln2 are not the same and x is a number ranging from greater than 0 to less than 4, La₃NdO₆, LaNd₃O₆, La_(1.5)Nd_(2.5)O₆, La_(2.5)Nd_(1.5)O₆, La_(3.2)Nd_(0.8)O₆, La_(3.5)Nd_(0.5)O₆, La_(3.8)Nd_(0.2)O₆, Y—La, Zr—La, Pr—La or Ce—La or combinations thereof. In other various embodiments, the lanthanide oxide nanowire catalyst comprises a C2 selectivity of greater than 50% and a methane conversion of greater than 20% when the lanthanide oxide nanowire catalyst is employed as a heterogenous catalyst in the oxidative coupling of methane at a temperature of 750° C. or less.

In various embodiments, of any of the above nanowire catalysts, the nanowire catalyst comprises a C2 selectivity of greater than 50% and a methane conversion of greater than 20% when the nanowire catalyst is employed as a heterogenous catalyst in the oxidative coupling of methane at a temperature of 750° C. or less, 700° C. or less, 650° C. or less or even 600° C. or less.

In more embodiments, of any of the above nanowire catalysts, the nanowire catalyst comprises a C2 selectivity of greater than 50%, greater than 55%, greater than 60%, greater than 65%, greater than 70%, or even greater than 75%, and a methane conversion of greater than 20% when the nanowire catalyst is employed as a heterogenous catalyst in the oxidative coupling of methane at a temperature of 750° C. or less.

In other embodiments, of any of the above catalysts, the catalyst comprises a C2 selectivity of greater than 50%, and a methane conversion of greater than 20%, greater than 25%, greater than 30%, greater than 35%, greater than 40%, greater than 45%, or even greater than 50% when the rare earth oxide catalyst is employed as a heterogenous catalyst in the oxidative coupling of methane at a temperature of 750° C. or less. In some embodiments of the foregoing, the methan conversion and C2 selectivity are calculated based on a single pass basis (i.e., the percent of methane converted or C2 selectivity upon a single pass over the catalyst or catalytic bed, etc.) In some embodiments, the foregoing doped nanowires comprise 1, 2, 3 or four doping elements. In other embodiments, the nanowires comprise more than four doping elements, for example, 5, 6, 7, 8, 9, 10 or even more doping elements. In this regard, each dopant may be present in the nanowires (for example any of the nanowires disclosed in Tables 9-12) in up to 75% by weight. For example, in one embodiment the concentration of a first doping element ranges from 0.01% to 1% w/w, 1%-5% w/w, 5%-10% w/w. 10%-20% ww, 20%-30% w/w, 30%-40% w/w or 40%-50% w/w, for example about 1% w/w, about 2% w/w, about 3% w/w, about 4% w/w, about 5% w/w, about 6% w/w, about 7% w/w, about 8% w/w, about 9% w/w, about 10% w/w, about 11% w/w, about 12% w/w, about 13% w/w, about 14% w/w, about 15% w/w, about 16% w/w, about 17% w/w, about 18% w/w, about 19% w/w or about 20% w/w.

In other embodiments, the concentration of a second doping element (when present) ranges from 0.01% to 1% w/w, 1%-5% w/w, 5%-10% w/w. 10%-20% ww, 20%-30% w/w, 30%-40% w/w or 40%-50% w/w, for example about 1% w/w, about 2% w/w, about 3% w/w, about 4% w/w, about 5% w/w, about 6% w/w, about 7% w/w, about 8% w/w, about 9% w/w, about 10% w/w, about 11% w/w, about 12% w/w, about 13% w/w, about 14% w/w, about 15% w/w, about 16% w/w, about 17% w/w, about 18% w/w, about 19% w/w or about 20% w/w.

In other embodiments, the concentration of a third doping element (when present) ranges from 0.01% to 1% w/w, 1%-5% w/w, 5%-10% w/w. 10%-20% ww, 20%-30% w/w, 30%-40% w/w or 40%-50% w/w, for example about 1% w/w, about 2% w/w, about 3% w/w, about 4% w/w, about 5% w/w, about 6% w/w, about 7% w/w, about 8% w/w, about 9% w/w, about 10% w/w, about 11% w/w, about 12% w/w, about 13% w/w, about 14% w/w, about 15% w/w, about 16% w/w, about 17% w/w, about 18% w/w, about 19% w/w or about 20% w/w.

In other embodiments, the concentration of a fourth doping element (when present) ranges from 0.01% to 1% w/w, 1%-5% w/w, 5%-10% w/w. 10%-20% ww, 20%-30% w/w, 30%-40% w/w or 40%-50% w/w, for example about 1% w/w, about 2% w/w, about 3% w/w, about 4% w/w, about 5% w/w, about 6% w/w, about 7% w/w, about 8% w/w, about 9% w/w, about 10% w/w, about 11% w/w, about 12% w/w, about 13% w/w, about 14% w/w, about 15% w/w, about 16% w/w, about 17% w/w, about 18% w/w, about 19% w/w or about 20% w/w.

In other embodiments, the concentration of the dopant is measured in terms of atomic percent (at/at). In some of these embodiments, each dopant may be present in the nanowires (for example any of the nanowires disclosed in Tables 1-12) in up to 75% at/at. For example, in one embodiment the concentration of a first doping element ranges from 0.01% to 1% at/at, 1%-5% at/at, 5%-10% at/at, 10%-20% at/at, 20%-30% at/at, 30%-40% at/at or 40%-50% at/at, for example about 1% at/at, about 2% at/at, about 3% at/at, about 4% at/at, about 5% at/at, about 6% at/at, about 7% at/at, about 8% at/at, about 9% at/at, about 10% at/at, about 11% at/at, about 12% at/at, about 13% at/at, about 14% at/at, about 15% at/at, about 16% at/at, about 17% at/at, about 18% at/at, about 19% at/at or about 20% at/at.

In other embodiments, the concentration of a second doping element (when present) ranges from 0.01% to 1% at/at, 1%-5% at/at, 5%-10% at/at, 10%-20% ww, 20%-30% at/at, 30%-40% at/at or 40%-50% at/at, for example about 1% at/at, about 2% at/at, about 3% at/at, about 4% at/at, about 5% at/at, about 6% at/at, about 7% at/at, about 8% at/at, about 9% at/at, about 10% at/at, about 11% at/at, about 12% at/at, about 13% at/at, about 14% at/at, about 15% at/at, about 16% at/at, about 17% at/at, about 18% at/at, about 19% at/at or about 20% at/at.

In other embodiments, the concentration of a third doping element (when present) ranges from 0.01% to 1% at/at, 1%-5% at/at, 5%-10% at/at, 10%-20% ww, 20%-30% at/at, 30%-40% at/at or 40%-50% at/at, for example about 1% at/at, about 2% at/at, about 3% at/at, about 4% at/at, about 5% at/at, about 6% at/at, about 7% at/at, about 8% at/at, about 9% at/at, about 10% at/at, about 11% at/at, about 12% at/at, about 13% at/at, about 14% at/at, about 15% at/at, about 16% at/at, about 17% at/at, about 18% at/at, about 19% at/at or about 20% at/at.

In other embodiments, the concentration of a fourth doping element (when present) ranges from 0.01% to 1% at/at, 1%-5% at/at, 5%-10% at/at, 10%-20% ww, 20%-30% at/at, 30%-40% at/at or 40%-50% at/at, for example about 1% at/at, about 2% at/at, about 3% at/at, about 4% at/at, about 5% at/at, about 6% at/at, about 7% at/at, about 8% at/at, about 9% at/at, about 10% at/at, about 11% at/at, about 12% at/at, about 13% at/at, about 14% at/at, about 15% at/at, about 16% at/at, about 17% at/at, about 18% at/at, about 19% at/at or about 20% at/at.

Accordingly, any of the doped nanowires described above or in Tables 1-12, may comprise any of the foregoing doping concentrations.

Furthermore, different catalytic characteristics of the above doped nanowires can be varied or “tuned” based on the method used to prepare them. For example, in one embodiment the above nanowires (and the nanowires of Tables 1-12) are prepared using a biological templating approach, for example phage. In other embodiments, the nanowires are prepared via a hydrothermal or sol gel approach (i.e., a non-templated approach). Some embodiments for preparing the nanowires (e.g., rare earth nanowires) comprise preparing the nanowires directly from the corresponding oxide or via a metal hydroxide gel approach. Such methods are described in more detail herein and other methods are known in the art. In addition, the above dopants may be incorporated either before or after (or combinations thereof) an optional calcification step as described herein.

In other embodiments, the nanowires comprise a mixed oxide selected from a Y—La mixed oxide doped with Na. (Y ranges from 5 to 20% of La mol/mol); a Zr—La mixed oxide doped with Na (Zr ranges from 1 to 5% of La mo/mol); a Pr—La mixed oxide doped with a group 1 element (Pr ranges from 2 to 6% of La mol/mol); and a Ce—La mixed oxide doped with a group 1 element (Ce ranges from 5 to 20% of La mol/mol). As used herein, the notation “M1-M2”, wherein M1 and M2 are each independently metals refers to a mixed metal oxide comprising the two metals. M1 and M2 may be present in equal or different amounts (at/at).

Some embodiments of the metal oxides disclosed herein can be in the form of oxides, oxyhydroxides, hydroxides, oxycarbonates or combination thereof after being exposed to moisture, carbon dioxide, undergoing incomplete calcination or combination thereof.

It is contemplated that any one or more of the dopants disclosed herein can be combined with any one of the nanowires disclosed herein to form a doped nanowire comprising one, two, three or more dopants. Tables 1-12 below show exemplary doped nanowires in accordance with various specific embodiments. Dopants (Dop) are shown in the horizontal rows and base nanowire catalyst (NW) in the vertical columns for Tables 1-8, and dopants are shown in the vertical columns and base nanowire catalyst in the horizontal rows for Tables 9-12. The resulting doped catalysts are shown in the intersecting cells in all tables. In some embodiments, the doped nanowires shown in tables 1-12 are doped with one, two, three or more additional dopants.

TABLE 1 NANOWIRES (NW) DOPED WITH SPECIFIC DOPANTS (DOP) Dop NW Li Na K Rb Li₂O Li/ Na/ K/ Rb/ Li₂O Li₂O Li₂O Li₂O Na₂O Li/ Na/ K/ Rb/ Na₂O Na₂O Na₂O Na₂O K₂O Li/ Na/ K/ Rb/ K₂O K₂O K₂O K₂O Rb₂O Li/ Na/ K/ Rb/ Rb₂O Rb₂O Rb₂O Rb₂O Cs₂O Li/ Na/ K/ Rb/ Cs₂O Cs₂O Cs₂O Cs₂O BeO Li/ Na/ K/ Rb/ BeO BeO BeO BeO MgO Li/ Na/ K/ Rb/ MgO MgO MgO MgO CaO Li/ Na/ K/ Rb/ CaO CaO CaO CaO SrO Li/ Na/ K/ Rb/ SrO SrO SrO SrO BaO Li/ Na/ K/ Rb/ BaO BaO BaO BaO Sc₂O₃ Li/ Na/ K/ Rb/ Sc₂O₃ Sc₂O₃ Sc₂O₃ Sc₂O₃ Y₂O₃ Li/ Na/ K/ Rb/ Y₂O₃ Y₂O₃ Y₂O₃ Y₂O₃ La₂O₃ Li/ Na/ K/ Rb/ La₂O₃ La₂O₃ La₂O₃ La₂O₃ CeO₂ Li/ Na/ K/ Rb/ CeO₂ CeO₂ CeO₂ CeO₂ Ce₂O₃ Li/ Na/ K/ Rb/ Ce₂O₃ Ce₂O₃ Ce₂O₃ Ce₂O₃ Pr₂O₃ Li/ Na/ K/ Rb/ Pr₂O₃ Pr₂O₃ Pr₂O₃ Pr₂O₃ Nd₂O₃ Li/ Na/ K/ Rb/ Nd₂O₃ Nd₂O₃ Nd₂O₃ Nd₂O₃ Sm₂O₃ Li/ Na/ K/ Rb/ Sm₂O₃ Sm₂O₃ Sm₂O₃ Sm₂O₃ Eu₂O₃ Li/ Na/ K/ Rb/ Eu₂O₃ Eu₂O₃ Eu₂O₃ Eu₂O₃ Gd₂O₃ Li/ Na/ K/ Rb/ Gd₂O₃ Gd₂O₃ Gd₂O₃ Gd₂O₃ Tb₂O₃ Li/ Na/ K/ Rb/ Tb₂O₃ Tb₂O₃ Tb₂O₃ Tb₂O₃ TbO₂ Li/ Na/ K/ Rb/ TbO₂ TbO₂ TbO₂ TbO₂ Tb₆O₁₁ Li/ Na/ K/ Rb/ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Dy₂O₃ Li/ Na/ K/ Rb/ Dy₂O₃ Dy₂O₃ Dy₂O₃ Dy₂O₃ Ho₂O₃ Li/ Na/ K/ Rb/ Ho₂O₃ Ho₂O₃ Ho₂O₃ Ho₂O₃ Er₂O₃ Li/ Na/ K/ Rb/ Er₂O₃ Er₂O₃ Er₂O₃ Er₂O₃ Tm₂O₃ Li/ Na/ K/ Rb/ Tm₂O₃ Tm₂O₃ Tm₂O₃ Tm₂O₃ Yb₂O₃ Li/ Na/ K/ Rb/ Yb₂O₃ Yb₂O₃ Yb₂O₃ Yb₂O₃ Lu₂O₃ Li/ Na/ K/ Rb/ Lu₂O₃ Lu₂O₃ Lu₂O₃ Lu₂O₃ Ac₂O₃ Li/ Na/ K/ Rb/ Ac₂O₃ Ac₂O₃ Ac₂O₃ Ac₂O₃ Th₂O₃ Li/ Na/ K/ Rb/ Th₂O₃ Th₂O₃ Th₂O₃ Th₂O₃ ThO₂ Li/ Na/ K/ Rb/ ThO₂ ThO₂ ThO₂ ThO₂ Pa₂O₃ Li/ Na/ K/ Rb/ Pa₂O₃ Pa₂O₃ Pa₂O₃ Pa₂O₃ PaO₂ Li/ Na/ K/ Rb/ PaO₂ PaO₂ PaO₂ PaO₂ TiO₂ Li/ Na/ K/ Rb/ TiO₂ TiO₂ TiO₂ TiO₂ TiO Li/ Na/ K/ Rb/ TiO TiO TiO TiO Ti₂O₃ Li/ Na/ K/ Rb/ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₃O Li/ Na/ K/ Rb/ Ti₃O Ti₃O Ti₃O Ti₃O Ti₂O Li/ Na/ K/ Rb/ Ti₂O Ti₂O Ti₂O Ti₂O Ti₃O₅ Li/ Na/ K/ Rb/ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₄O₇ Li/ Na/ K/ Rb/ Ti₄O₇ Ti₄O₇ Ti₄O₇ Ti₄O₇ ZrO₂ Li/ Na/ K/ Rb/ ZrO₂ ZrO₂ ZrO₂ ZrO₂ HfO₂ Li/ Na/ K/ Rb/ HfO₂ HfO₂ HfO₂ HfO₂ VO Li/ Na/ K/ Rb/ VO VO VO VO V₂O₃ Li/ Na/ K/ Rb/ V₂O₃ V₂O₃ V₂O₃ V₂O₃ VO₂ Li/ Na/ K/ Rb/ VO₂ VO₂ VO₂ VO₂ V₂O₅ Li/ Na/ K/ Rb/ V₂O₅ V₂O₅ V₂O₅ V₂O₅ V₃O₇ Li/ Na/ K/ Rb/ V₃O₇ V₃O₇ V₃O₇ V₃O₇ V₄O₉ Li/ Na/ K/ Rb/ V₄O₉ V₄O₉ V₄O₉ V₄O₉ V₆O₁₃ Li/ Na/ K/ Rb/ V₆O₁₃ V₆O₁₃ V₆O₁₃ V₆O₁₃ NbO Li/ Na/ K/ Rb/ NbO NbO NbO NbO NbO₂ Li/ Na/ K/ Rb/ NbO₂ NbO₂ NbO₂ NbO₂ Nb₂O₅ Li/ Na/ K/ Rb/ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₈O₁₉ Li/ Na/ K/ Rb/ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ Li/ Na/ K/ Rb/ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₂O₂₉ Li/ Na/ K/ Rb/ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₄₇O₁₁₆ Li/ Na/ K/ Rb/ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Ta₂O₅ Li/ Na/ K/ Rb/ Ta₂O₅ Ta₂O₅ Ta₂O₅ Ta₂O₅ CrO Li/ Na/ K/ Rb/ CrO CrO CrO CrO Cr₂O₃ Li/ Na/ K/ Rb/ Cr₂O₃ Cr₂O₃ Cr₂O₃ Cr₂O₃ CrO₂ Li/ Na/ K/ Rb/ CrO₂ CrO₂ CrO₂ CrO₂ CrO₃ Li/ Na/ K/ Rb/ CrO₃ CrO₃ CrO₃ CrO₃ Cr₈O₂₁ Li/ Na/ K/ Rb/ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ MoO₂ Li/ Na/ K/ Rb/ MoO₂ MoO₂ MoO₂ MoO₂ MoO₃ Li/ Na/ K/ Rb/ MoO₃ MoO₃ MoO₃ MoO₃ W₂O₃ Li/ Na/ K/ Rb/ W₂O₃ W₂O₃ W₂O₃ W₂O₃ WoO₂ Li/ Na/ K/ Rb/ WoO₂ WoO₂ WoO₂ WoO₂ WoO₃ Li/ Na/ K/ Rb/ WoO₃ WoO₃ WoO₃ WoO₃ MnO Li/ Na/ K/ Rb/ MnO MnO MnO MnO Mn/Mg/O Li/ Na/ K/ Rb/ Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn₃O₄ Li/ Na/ K/ Rb/ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₂O₃ Li/ Na/ K/ Rb/ Mn₂O₃ Mn₂O₃ Mn₂O₃ Mn₂O₃ MnO₂ Li/ Na/ K/ Rb/ MnO₂ MnO₂ MnO₂ MnO₂ Mn₂O₇ Li/ Na/ K/ Rb/ Mn₂O₇ Mn₂O₇ Mn₂O₇ Mn₂O₇ ReO₂ Li/ Na/ K/ Rb/ ReO₂ ReO₂ ReO₂ ReO₂ ReO₃ Li/ Na/ K/ Rb/ ReO₃ ReO₃ ReO₃ ReO₃ Re₂O₇ Li/ Na/ K/ Rb/ Re₂O₇ Re₂O₇ Re₂O₇ Re₂O₇ Mg₃Mn₃—B₂O₁₀ Li/ Na/ K/ Rb/ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂ Li/ Na/ K/ Rb/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ NaWO₄ Li/ Na/ K/ Rb/ NaWO₄ NaWO₄ NaWO₄ NaWO₄ Mg₆MnO₈ Li/ Na/ K/ Rb/ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ (Li,Mg)₆—MnO₈ Li/ Na/ K/ Rb/ (Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ Mn₂O₄ Li/ Na/ K/ Rb/ Mn₂O₄ Mn₂O₄ Mn₂O₄ Mn₂O₄ Na₄P₂O₇ Li/ Na/ K/ Rb/ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Mo₂O₈ Li/ Na/ K/ Rb/ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mn₃O₄/ Li/ Na/ K/ Rb/ WO₄ Mn₃O₄/ Mn₃O₄/ Mn₃O₄/ Mn₃O₄/ WO₄ WO₄ WO₄ WO₄ Na₂WO₄ Li/ Na/ K/ Rb/ Na₂WO₄ Na₂WO₄ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ Li/ Na/ K/ Rb/ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ NaMnO₄−/ Li/ Na/ K/ Rb/ MgO NaMnO₄−/ NaMnO₄−/ NaMnO₄−/ NaMnO₄−/ MgO MgO MgO MgO Na₁₀Mn—W₅O₁₇ Li/ Na/ K/ Rb/ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ La₃NdO₆ Li/ Na/ K/ Rb/ La₃NdO₆ La₃NdO₆ La₃NdO₆ La₃NdO₆ LaNd₃O₆ Li/ Na/ K/ Rb/ LaNd₃O₆ LaNd₃O₆ LaNd₃O₆ LaNd₃O₆ La_(1,5)Nd_(2,5)O₆ Li/ Na/ K/ Rb/ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(2,5)Nd_(1,5)O₆ Li/ Na/ K/ Rb/ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(3,2)Nd_(0,8)O₆ Li/ Na/ K/ Rb/ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,5)Nd_(0,5)O₆ Li/ Na/ K/ Rb/ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,8)Nd_(0,2)O₆ Li/ Na/ K/ Rb/ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ Y—La Li/ Na/ K/ Rb/ Y—La Y—La Y—La Y—La Zr—La Li/ Na/ K/ Rb/ Zr—La Zr—La Zr—La Zr—La Pr—La Li/ Na/ K/ Rb/ Pr—La Pr—La Pr—La Pr—La Ce—La Li/ Na/ K/ Rb/ Ce—La Ce—La Ce—La Ce—La Dop NW Cs Be Mg Ca Li₂O Cs/ Be/ Mg/ Ca/ Li₂O Li₂O Li₂O Li₂O Na₂O Cs/ Be/ Mg/ Ca/ Na₂O Na₂O Na₂O Na₂O K₂O Cs/ Be/ Mg/ Ca/ K₂O K₂O K₂O K₂O Rb₂O Cs/ Be/ Mg/ Ca/ Rb₂O Rb₂O Rb₂O Rb₂O Cs₂O Cs/ Be/ Mg/ Ca/ Cs₂O Cs₂O Cs₂O Cs₂O BeO Cs/ Be/ Mg/ Ca/ BeO BeO BeO BeO MgO Cs/ Be/ Mg/ Ca/ MgO MgO MgO MgO CaO Cs/ Be/ Mg/ Ca/ CaO CaO CaO CaO SrO Cs/ Be/ Mg/ Ca/ SrO SrO SrO SrO BaO Cs/ Be/ Mg/ Ca/ BaO BaO BaO BaO Sc₂O₃ Cs/ Be/ Mg/ Ca/ Sc₂O₃ Sc₂O₃ Sc₂O₃ Sc₂O₃ Y₂O₃ Cs/ Be/ Mg/ Ca/ Y₂O₃ Y₂O₃ Y₂O₃ Y₂O₃ La₂O₃ Cs/ Be/ Mg/ Ca/ La₂O₃ La₂O₃ La₂O₃ La₂O₃ CeO₂ Cs/ Be/ Mg/ Ca/ CeO₂ CeO₂ CeO₂ CeO₂ Ce₂O₃ Cs/ Be/ Mg/ Ca/ Ce₂O₃ Ce₂O₃ Ce₂O₃ Ce₂O₃ Pr₂O₃ Cs/ Be/ Mg/ Ca/ Pr₂O₃ Pr₂O₃ Pr₂O₃ Pr₂O₃ Nd₂O₃ Cs/ Be/ Mg/ Ca/ Nd₂O₃ Nd₂O₃ Nd₂O₃ Nd₂O₃ Sm₂O₃ Cs/ Be/ Mg/ Ca/ Sm₂O₃ Sm₂O₃ Sm₂O₃ Sm₂O₃ Eu₂O₃ Cs/ Be/ Mg/ Ca/ Eu₂O₃ Eu₂O₃ Eu₂O₃ Eu₂O₃ Gd₂O₃ Cs/ Be/ Mg/ Ca/ Gd₂O₃ Gd₂O₃ Gd₂O₃ Gd₂O₃ Tb₂O₃ Cs/ Be/ Mg/ Ca/ Tb₂O₃ Tb₂O₃ Tb₂O₃ Tb₂O₃ TbO₂ Cs/ Be/ Mg/ Ca/ TbO₂ TbO₂ TbO₂ TbO₂ Tb₆O₁₁ Cs/ Be/ Mg/ Ca/ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Dy₂O₃ Cs/ Be/ Mg/ Ca/ Dy₂O₃ Dy₂O₃ Dy₂O₃ Dy₂O₃ Ho₂O₃ Cs/ Be/ Mg/ Ca/ Ho₂O₃ Ho₂O₃ Ho₂O₃ Ho₂O₃ Er₂O₃ Cs/ Be/ Mg/ Ca/ Er₂O₃ Er₂O₃ Er₂O₃ Er₂O₃ Tm₂O₃ Cs/ Be/ Mg/ Ca/ Tm₂O₃ Tm₂O₃ Tm₂O₃ Tm₂O₃ Yb₂O₃ Cs/ Be/ Mg/ Ca/ Yb₂O₃ Yb₂O₃ Yb₂O₃ Yb₂O₃ Lu₂O₃ Cs/ Be/ Mg/ Ca/ Lu₂O₃ Lu₂O₃ Lu₂O₃ Lu₂O₃ Ac₂O₃ Cs/ Be/ Mg/ Ca/ Ac₂O₃ Ac₂O₃ Ac₂O₃ Ac₂O₃ Th₂O₃ Cs/ Be/ Mg/ Ca/ Th₂O₃ Th₂O₃ Th₂O₃ Th₂O₃ ThO₂ Cs/ Be/ Mg/ Ca/ ThO₂ ThO₂ ThO₂ ThO₂ Pa₂O₃ Cs/ Be/ Mg/ Ca/ Pa₂O₃ Pa₂O₃ Pa₂O₃ Pa₂O₃ PaO₂ Cs/ Be/ Mg/ Ca/ PaO₂ PaO₂ PaO₂ PaO₂ TiO₂ Cs/ Be/ Mg/ Ca/ TiO₂ TiO₂ TiO₂ TiO₂ TiO Cs/ Be/ Mg/ Ca/ TiO TiO TiO TiO Ti₂O₃ Cs/ Be/ Mg/ Ca/ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₃O Cs/ Be/ Mg/ Ca/ Ti₃O Ti₃O Ti₃O Ti₃O Ti₂O Cs/ Be/ Mg/ Ca/ Ti₂O Ti₂O Ti₂O Ti₂O Ti₃O₅ Cs/ Be/ Mg/ Ca/ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₄O₇ Cs/ Be/ Mg/ Ca/ Ti₄O₇ Ti₄O₇ Ti₄O₇ Ti₄O₇ ZrO₂ Cs/ Be/ Mg/ Ca/ ZrO₂ ZrO₂ ZrO₂ ZrO₂ HfO₂ Cs/ Be/ Mg/ Ca/ HfO₂ HfO₂ HfO₂ HfO₂ VO Cs/ Be/ Mg/ Ca/ VO VO VO VO V₂O₃ Cs/ Be/ Mg/ Ca/ V₂O₃ V₂O₃ V₂O₃ V₂O₃ VO₂ Cs/ Be/ Mg/ Ca/ VO₂ VO₂ VO₂ VO₂ V₂O₅ Cs/ Be/ Mg/ Ca/ V₂O₅ V₂O₅ V₂O₅ V₂O₅ V₃O₇ Cs/ Be/ Mg/ Ca/ V₃O₇ V₃O₇ V₃O₇ V₃O₇ V₄O₉ Cs/ Be/ Mg/ Ca/ V₄O₉ V₄O₉ V₄O₉ V₄O₉ V₆O₁₃ Cs/ Be/ Mg/ Ca/ V₆O₁₃ V₆O₁₃ V₆O₁₃ V₆O₁₃ NbO Cs/ Be/ Mg/ Ca/ NbO NbO NbO NbO NbO₂ Cs/ Be/ Mg/ Ca/ NbO₂ NbO₂ NbO₂ NbO₂ Nb₂O₅ Cs/ Be/ Mg/ Ca/ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₈O₁₉ Cs/ Be/ Mg/ Ca/ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ Cs/ Be/ Mg/ Ca/ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₂O₂₉ Cs/ Be/ Mg/ Ca/ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₄₇O₁₁₆ Cs/ Be/ Mg/ Ca/ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Ta₂O₅ Cs/ Be/ Mg/ Ca/ Ta₂O₅ Ta₂O₅ Ta₂O₅ Ta₂O₅ CrO Cs/ Be/ Mg/ Ca/ CrO CrO CrO CrO Cr₂O₃ Cs/ Be/ Mg/ Ca/ Cr₂O₃ Cr₂O₃ Cr₂O₃ Cr₂O₃ CrO₂ Cs/ Be/ Mg/ Ca/ CrO₂ CrO₂ CrO₂ CrO₂ CrO₃ Cs/ Be/ Mg/ Ca/ CrO₃ CrO₃ CrO₃ CrO₃ Cr₈O₂₁ Cs/ Be/ Mg/ Ca/ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ MoO₂ Cs/ Be/ Mg/ Ca/ MoO₂ MoO₂ MoO₂ MoO₂ MoO₃ Cs/ Be/ Mg/ Ca/ MoO₃ MoO₃ MoO₃ MoO₃ W₂O₃ Cs/ Be/ Mg/ Ca/ W₂O₃ W₂O₃ W₂O₃ W₂O₃ WoO₂ Cs/ Be/ Mg/ Ca/ WoO₂ WoO₂ WoO₂ WoO₂ WoO₃ Cs/ Be/ Mg/ Ca/ WoO₃ WoO₃ WoO₃ WoO₃ MnO Cs/ Be/ Mg/ Ca/ MnO MnO MnO MnO Mn/Mg/O Cs/ Be/ Mg/ Ca/ Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn₃O₄ Cs/ Be/ Mg/ Ca/ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₂O₃ Cs/ Be/ Mg/ Ca/ Mn₂O₃ Mn₂O₃ Mn₂O₃ Mn₂O₃ MnO₂ Cs/ Be/ Mg/ Ca/ MnO₂ MnO₂ MnO₂ MnO₂ Mn₂O₇ Cs/ Be/ Mg/ Ca/ Mn₂O₇ Mn₂O₇ Mn₂O₇ Mn₂O₇ ReO₂ Cs/ Be/ Mg/ Ca/ ReO₂ ReO₂ ReO₂ ReO₂ ReO₃ Cs/ Be/ Mg/ Ca/ ReO₃ ReO₃ ReO₃ ReO₃ Re₂O₇ Cs/ Be/ Mg/ Ca/ Re₂O₇ Re₂O₇ Re₂O₇ Re₂O₇ Mg₃Mn₃—B₂O₁₀ Cs/ Be/ Mg/ Ca/ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂ Cs/ Be/ Mg/ Ca/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ NaWO₄ Cs/ Be/ Mg/ Ca/ NaWO₄ NaWO₄ NaWO₄ NaWO₄ Mg₆MnO₈ Cs/ Be/ Mg/ Ca/ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ (Li,Mg)₆—MnO₈ Cs/ Be/ Mg/ Ca/ (Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ Mn₂O₄ Cs/ Be/ Mg/ Ca/ Mn₂O₄ Mn₂O₄ Mn₂O₄ Mn₂O₄ Na₄P₂O₇ Cs/ Be/ Mg/ Ca/ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Mo₂O₈ Cs/ Be/ Mg/ Ca/ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mn₃O₄/ Cs/ Be/ Mg/ Ca/ WO₄ Mn₃O₄/ Mn₃O₄/ Mn₃O₄/ Mn₃O₄/ WO₄ WO₄ WO₄ WO₄ Na₂WO₄ Cs/ Be/ Mg/ Ca/ Na₂WO₄ Na₂WO₄ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ Cs/ Be/ Mg/ Ca/ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ NaMnO₄−/ Cs/ Be/ Mg/ Ca/ MgO NaMnO₄−/ NaMnO₄−/ NaMnO₄−/ NaMnO₄−/ MgO MgO MgO MgO Na₁₀Mn—W₅O₁₇ Cs/ Be/ Mg/ Ca/ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ La₃NdO₆ Cs/ Be/ Mg/ Ca/ La₃NdO₆ La₃NdO₆ La₃NdO₆ La₃NdO₆ LaNd₃O₆ Cs/ Be/ Mg/ Ca/ LaNd₃O₆ LaNd₃O₆ LaNd₃O₆ LaNd₃O₆ La_(1,5)Nd_(2,5)O₆ Cs/ Be/ Mg/ Ca/ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(2,5)Nd_(1,5)O₆ Cs/ Be/ Mg/ Ca/ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(3,2)Nd_(0,8)O₆ Cs/ Be/ Mg/ Ca/ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,5)Nd_(0,5)O₆ Cs/ Be/ Mg/ Ca/ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,8)Nd_(0,2)O₆ Cs/ Be/ Mg/ Ca/ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ Y—La Cs/ Be/ Mg/ Ca/ Y—La Y—La Y—La Y—La Zr—La Cs/ Be/ Mg/ Ca/ Zr—La Zr—La Zr—La Zr—La Pr—La Cs/ Be/ Mg/ Ca/ Pr—La Pr—La Pr—La Pr—La Ce—La Cs/ Be/ Mg/ Ca/ Ce—La Ce—La Ce—La Ce—La

TABLE 2 NANOWIRES (NW) DOPED WITH SPECIFIC DOPANTS (DOP) Dop NW Sr Ba B P Li₂O Sr/ Ba/ B/ P/ Li₂O Li₂O Li₂O Li₂O Na₂O Sr/ Ba/ B/ P/ Na₂O Na₂O Na₂O Na₂O K₂O Sr/ Ba/ B/ P/ K₂O K₂O K₂O K₂O Rb₂O Sr/ Ba/ B/ P/ Rb₂O Rb₂O Rb₂O Rb₂O Cs₂O Sr/ Ba/ B/ P/ Cs₂O Cs₂O Cs₂O Cs₂O BeO Sr/ Ba/ B/ P/ BeO BeO BeO BeO MgO Sr/ Ba/ B/ P/ MgO MgO MgO MgO CaO Sr/ Ba/ B/ P/ CaO CaO CaO CaO SrO Sr/ Ba/ B/ P/ SrO SrO SrO SrO BaO Sr/ Ba/ B/ P/ BaO BaO BaO BaO Sc₂O₃ Sr/ Ba/ B/ P/ Sc₂O₃ Sc₂O₃ Sc₂O₃ Sc₂O₃ Y₂O₃ Sr/ Ba/ B/ P/ Y₂O₃ Y₂O₃ Y₂O₃ Y₂O₃ La₂O₃ Sr/ Ba/ B/ P/ La₂O₃ La₂O₃ La₂O₃ La₂O₃ CeO₂ Sr/ Ba/ B/ P/ CeO₂ CeO₂ CeO₂ CeO₂ Ce₂O₃ Sr/ Ba/ B/ P/ Ce₂O₃ Ce₂O₃ Ce₂O₃ Ce₂O₃ Pr₂O₃ Sr/ Ba/ B/ P/ Pr₂O₃ Pr₂O₃ Pr₂O₃ Pr₂O₃ Nd₂O₃ Sr/ Ba/ B/ P/ Nd₂O₃ Nd₂O₃ Nd₂O₃ Nd₂O₃ Sm₂O₃ Sr/ Ba/ B/ P/ Sm₂O₃ Sm₂O₃ Sm₂O₃ Sm₂O₃ Eu₂O₃ Sr/ Ba/ B/ P/ Eu₂O₃ Eu₂O₃ Eu₂O₃ Eu₂O₃ Gd₂O₃ Sr/ Ba/ B/ P/ Gd₂O₃ Gd₂O₃ Gd₂O₃ Gd₂O₃ Tb₂O₃ Sr/ Ba/ B/ P/ Tb₂O₃ Tb₂O₃ Tb₂O₃ Tb₂O₃ TbO₂ Sr/ Ba/ B/ P/ TbO₂ TbO₂ TbO₂ TbO₂ Tb₆O₁₁ Sr/ Ba/ B/ P/ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Dy₂O₃ Sr/ Ba/ B/ P/ Dy₂O₃ Dy₂O₃ Dy₂O₃ Dy₂O₃ Ho₂O₃ Sr/ Ba/ B/ P/ Ho₂O₃ Ho₂O₃ Ho₂O₃ Ho₂O₃ Er₂O₃ Sr/ Ba/ B/ P/ Er₂O₃ Er₂O₃ Er₂O₃ Er₂O₃ Tm₂O₃ Sr/ Ba/ B/ P/ Tm₂O₃ Tm₂O₃ Tm₂O₃ Tm₂O₃ Yb₂O₃ Sr/ Ba/ B/ P/ Yb₂O₃ Yb₂O₃ Yb₂O₃ Yb₂O₃ Lu₂O₃ Sr/ Ba/ B/ P/ Lu₂O₃ Lu₂O₃ Lu₂O₃ Lu₂O₃ Ac₂O₃ Sr/ Ba/ B/ P/ Ac₂O₃ Ac₂O₃ Ac₂O₃ Ac₂O₃ Th₂O₃ Sr/ Ba/ B/ P/ Th₂O₃ Th₂O₃ Th₂O₃ Th₂O₃ ThO₂ Sr/ Ba/ B/ P/ ThO₂ ThO₂ ThO₂ ThO₂ Pa₂O₃ Sr/ Ba/ B/ P/ Pa₂O₃ Pa₂O₃ Pa₂O₃ Pa₂O₃ PaO₂ Sr/ Ba/ B/ P/ PaO₂ PaO₂ PaO₂ PaO₂ TiO₂ Sr/ Ba/ B/ P/ TiO₂ TiO₂ TiO₂ TiO₂ TiO Sr/ Ba/ B/ P/ TiO TiO TiO TiO Ti₂O₃ Sr/ Ba/ B/ P/ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₃O Sr/ Ba/ B/ P/ Ti₃O Ti₃O Ti₃O Ti₃O Ti₂O Sr/ Ba/ B/ P/ Ti₂O Ti₂O Ti₂O Ti₂O Ti₃O₅ Sr/ Ba/ B/ P/ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₄O₇ Sr/ Ba/ B/ P/ Ti₄O₇ Ti₄O₇ Ti₄O₇ Ti₄O₇ ZrO₂ Sr/ Ba/ B/ P/ ZrO₂ ZrO₂ ZrO₂ ZrO₂ HfO₂ Sr/ Ba/ B/ P/ HfO₂ HfO₂ HfO₂ HfO₂ VO Sr/ Ba/ B/ P/ VO VO VO VO V₂O₃ Sr/ Ba/ B/ P/ V₂O₃ V₂O₃ V₂O₃ V₂O₃ VO₂ Sr/ Ba/ B/ P/ VO₂ VO₂ VO₂ VO₂ V₂O₅ Sr/ Ba/ B/ P/ V₂O₅ V₂O₅ V₂O₅ V₂O₅ V₃O₇ Sr/ Ba/ B/ P/ V₃O₇ V₃O₇ V₃O₇ V₃O₇ V₄O₉ Sr/ Ba/ B/ P/ V₄O₉ V₄O₉ V₄O₉ V₄O₉ V₆O₁₃ Sr/ Ba/ B/ P/ V₆O₁₃ V₆O₁₃ V₆O₁₃ V₆O₁₃ NbO Sr/ Ba/ B/ P/ NbO NbO NbO NbO NbO₂ Sr/ Ba/ B/ P/ NbO₂ NbO₂ NbO₂ NbO₂ Nb₂O₅ Sr/ Ba/ B/ P/ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₈O₁₉ Sr/ Ba/ B/ P/ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ Sr/ Ba/ B/ P/ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₂O₂₉ Sr/ Ba/ B/ P/ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₄₇O₁₁₆ Sr/ Ba/ B/ P/ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Ta₂O₅ Sr/ Ba/ B/ P/ Ta₂O₅ Ta₂O₅ Ta₂O₅ Ta₂O₅ CrO Sr/ Ba/ B/ P/ CrO CrO CrO CrO Cr₂O₃ Sr/ Ba/ B/ P/ Cr₂O₃ Cr₂O₃ Cr₂O₃ Cr₂O₃ CrO₂ Sr/ Ba/ B/ P/ CrO₂ CrO₂ CrO₂ CrO₂ CrO₃ Sr/ Ba/ B/ P/ CrO₃ CrO₃ CrO₃ CrO₃ Cr₈O₂₁ Sr/ Ba/ B/ P/ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ MoO₂ Sr/ Ba/ B/ P/ MoO₂ MoO₂ MoO₂ MoO₂ MoO₃ Sr/ Ba/ B/ P/ MoO₃ MoO₃ MoO₃ MoO₃ W₂O₃ Sr/ Ba/ B/ P/ W₂O₃ W₂O₃ W₂O₃ W₂O₃ WoO₂ Sr/ Ba/ B/ P/ WoO₂ WoO₂ WoO₂ WoO₂ WoO₃ Sr/ Ba/ B/ P/ WoO₃ WoO₃ WoO₃ WoO₃ MnO Sr/ Ba/ B/ P/ MnO MnO MnO MnO Mn/Mg/O Sr/ Ba/ B/ P/ Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn₃O₄ Sr/ Ba/ B/ P/ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₂O₃ Sr/ Ba/ B/ P/ Mn₂O₃ Mn₂O₃ Mn₂O₃ Mn₂O₃ MnO₂ Sr/ Ba/ B/ P/ MnO₂ MnO₂ MnO₂ MnO₂ Mn₂O₇ Sr/ Ba/ B/ P/ Mn₂O₇ Mn₂O₇ Mn₂O₇ Mn₂O₇ ReO₂ Sr/ Ba/ B/ P/ ReO₂ ReO₂ ReO₂ ReO₂ ReO₃ Sr/ Ba/ B/ P/ ReO₃ ReO₃ ReO₃ ReO₃ Re₂O₇ Sr/ Ba/ B/ P/ Re₂O₇ Re₂O₇ Re₂O₇ Re₂O₇ Mg₃Mn₃—B₂O₁₀ Sr/ Ba/ B/ P/ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂ Sr/ Ba/ B/ P/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ NaWO₄ Sr/ Ba/ B/ P/ NaWO₄ NaWO₄ NaWO₄ NaWO₄ Mg₆MnO₈ Sr/ Ba/ B/ P/ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ (Li,Mg)₆MnO₈ Sr/ Ba/ B/ P/ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ Mn₂O₄ Sr/ Ba/ B/ P/ Mn₂O₄ Mn₂O₄ Mn₂O₄ Mn₂O₄ Na₄P₂O₇ Sr/ Ba/ B/ P/ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Mo₂O₈ Sr/ Ba/ B/ P/ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mn₃O₄/WO₄ Sr/ Ba/ B/ P/ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Na₂WO₄ Sr/ Ba/ B/ P/ Na₂WO₄ Na₂WO₄ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ Sr/ Ba/ B/ P/ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ NaMnO₄/MgO Sr/ Ba/ B/ P/ NaMnO₄/MgO NaMnO₄/MgO NaMnO₄/MgO NaMnO₄/MgO Na₁₀Mn—W₅O₁₇ Sr/ Ba/ B/ P/ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ La₃NdO₆ Sr/ Ba/ B/ P/ La₃NdO₆ La₃NdO₆ La₃NdO₆ La₃NdO₆ LaNd₃O₆ Sr/ Ba/ B/ P/ LaNd₃O₆ LaNd₃O₆ LaNd₃O₆ LaNd₃O₆ La_(1,5)Nd_(2,5)O₆ Sr/ Ba/ B/ P/ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(2,5)Nd_(1,5)O₆ Sr/ Ba/ B/ P/ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(3,2)Nd_(0,8)O₆ Sr/ Ba/ B/ P/ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,5)Nd_(0,5)O₆ Sr/ Ba/ B/ P/ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,8)Nd_(0,2)O₆ Sr/ Ba/ B/ P/ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ Y—La Sr/ Ba/ B/ P/ Y—La Y—La Y—La Y—La Zr—La Sr/ Ba/ B/ P/ Zr—La Zr—La Zr—La Zr—La Pr—La Sr/ Ba/ B/ P/ Pr—La Pr—La Pr—La Pr—La Ce—La Sr/ Ba/ B/ P/ Ce—La Ce—La Ce—La Ce—La Dop NW S F Cl Li₂O S/ F/ Cl/ Li₂O Li₂O Li₂O Na₂O S/ F/ Cl/ Na₂O Na₂O Na₂O K₂O S/ F/ Cl/ K₂O K₂O K₂O Rb₂O S/ F/ Cl/ Rb₂O Rb₂O Rb₂O Cs₂O S/ F/ Cl/ Cs₂O Cs₂O Cs₂O BeO S/ F/ Cl/ BeO BeO BeO MgO S/ F/ Cl/ MgO MgO MgO CaO S/ F/ Cl/ CaO CaO CaO SrO S/ F/ Cl/ SrO SrO SrO BaO S/ F/ Cl/ BaO BaO BaO Sc₂O₃ S/ F/ Cl/ Sc₂O₃ Sc₂O₃ Sc₂O₃ Y₂O₃ S/ F/ Cl/ Y₂O₃ Y₂O₃ Y₂O₃ La₂O₃ S/ F/ Cl/ La₂O₃ La₂O₃ La₂O₃ CeO₂ S/ F/ Cl/ CeO₂ CeO₂ CeO₂ Ce₂O₃ S/ F/ Cl/ Ce₂O₃ Ce₂O₃ Ce₂O₃ Pr₂O₃ S/ F/ Cl/ Pr₂O₃ Pr₂O₃ Pr₂O₃ Nd₂O₃ S/ F/ Cl/ Nd₂O₃ Nd₂O₃ Nd₂O₃ Sm₂O₃ S/ F/ Cl/ Sm₂O₃ Sm₂O₃ Sm₂O₃ Eu₂O₃ S/ F/ Cl/ Eu₂O₃ Eu₂O₃ Eu₂O₃ Gd₂O₃ S/ F/ Cl/ Gd₂O₃ Gd₂O₃ Gd₂O₃ Tb₂O₃ S/ F/ Cl/ Tb₂O₃ Tb₂O₃ Tb₂O₃ TbO₂ S/ F/ Cl/ TbO₂ TbO₂ TbO₂ Tb₆O₁₁ S/ F/ Cl/ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Dy₂O₃ S/ F/ Cl/ Dy₂O₃ Dy₂O₃ Dy₂O₃ Ho₂O₃ S/ F/ Cl/ Ho₂O₃ Ho₂O₃ Ho₂O₃ Er₂O₃ S/ F/ Cl/ Er₂O₃ Er₂O₃ Er₂O₃ Tm₂O₃ S/ F/ Cl/ Tm₂O₃ Tm₂O₃ Tm₂O₃ Yb₂O₃ S/ F/ Cl/ Yb₂O₃ Yb₂O₃ Yb₂O₃ Lu₂O₃ S/ F/ Cl/ Lu₂O₃ Lu₂O₃ Lu₂O₃ Ac₂O₃ S/ F/ Cl/ Ac₂O₃ Ac₂O₃ Ac₂O₃ Th₂O₃ S/ F/ Cl/ Th₂O₃ Th₂O₃ Th₂O₃ ThO₂ S/ F/ Cl/ ThO₂ ThO₂ ThO₂ Pa₂O₃ S/ F/ Cl/ Pa₂O₃ Pa₂O₃ Pa₂O₃ PaO₂ S/ F/ Cl/ PaO₂ PaO₂ PaO₂ TiO₂ S/ F/ Cl/ TiO₂ TiO₂ TiO₂ TiO S/ F/ Cl/ TiO TiO TiO Ti₂O₃ S/ F/ Cl/ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₃O S/ F/ Cl/ Ti₃O Ti₃O Ti₃O Ti₂O S/ F/ Cl/ Ti₂O Ti₂O Ti₂O Ti₃O₅ S/ F/ Cl/ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₄O₇ S/ F/ Cl/ Ti₄O₇ Ti₄O₇ Ti₄O₇ ZrO₂ S/ F/ Cl/ ZrO₂ ZrO₂ ZrO₂ HfO₂ S/ F/ Cl/ HfO₂ HfO₂ HfO₂ VO S/ F/ Cl/ VO VO VO V₂O₃ S/ F/ Cl/ V₂O₃ V₂O₃ V₂O₃ VO₂ S/ F/ Cl/ VO₂ VO₂ VO₂ V₂O₅ S/ F/ Cl/ V₂O₅ V₂O₅ V₂O₅ V₃O₇ S/ F/ Cl/ V₃O₇ V₃O₇ V₃O₇ V₄O₉ S/ F/ Cl/ V₄O₉ V₄O₉ V₄O₉ V₆O₁₃ S/ F/ Cl/ V₆O₁₃ V₆O₁₃ V₆O₁₃ NbO S/ F/ Cl/ NbO NbO NbO NbO₂ S/ F/ Cl/ NbO₂ NbO₂ NbO₂ Nb₂O₅ S/ F/ Cl/ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₈O₁₉ S/ F/ Cl/ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ S/ F/ Cl/ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₂O₂₉ S/ F/ Cl/ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₄₇O₁₁₆ S/ F/ Cl/ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Ta₂O₅ S/ F/ Cl/ Ta₂O₅ Ta₂O₅ Ta₂O₅ CrO S/ F/ Cl/ CrO CrO CrO Cr₂O₃ S/ F/ Cl/ Cr₂O₃ Cr₂O₃ Cr₂O₃ CrO₂ S/ F/ Cl/ CrO₂ CrO₂ CrO₂ CrO₃ S/ F/ Cl/ CrO₃ CrO₃ CrO₃ Cr₈O₂₁ S/ F/ Cl/ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ MoO₂ S/ F/ Cl/ MoO₂ MoO₂ MoO₂ MoO₃ S/ F/ Cl/ MoO₃ MoO₃ MoO₃ W₂O₃ S/ F/ Cl/ W₂O₃ W₂O₃ W₂O₃ WoO₂ S/ F/ Cl/ WoO₂ WoO₂ WoO₂ WoO₃ S/ F/ Cl/ WoO₃ WoO₃ WoO₃ MnO S/ F/ Cl/ MnO MnO MnO Mn/Mg/O S/ F/ Cl/ Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn₃O₄ S/ F/ Cl/ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₂O₃ S/ F/ Cl/ Mn₂O₃ Mn₂O₃ Mn₂O₃ MnO₂ S/ F/ Cl/ MnO₂ MnO₂ MnO₂ Mn₂O₇ S/ F/ Cl/ Mn₂O₇ Mn₂O₇ Mn₂O₇ ReO₂ S/ F/ Cl/ ReO₂ ReO₂ ReO₂ ReO₃ S/ F/ Cl/ ReO₃ ReO₃ ReO₃ Re₂O₇ S/ F/ Cl/ Re₂O₇ Re₂O₇ Re₂O₇ Mg₃Mn₃—B₂O₁₀ S/ F/ Cl/ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂ S/ F/ Cl/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ NaWO₄ S/ F/ Cl/ NaWO₄ NaWO₄ NaWO₄ Mg₆MnO₈ S/ F/ Cl/ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ (Li,Mg)₆MnO₈ S/ F/ Cl/ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ Mn₂O₄ S/ F/ Cl/ Mn₂O₄ Mn₂O₄ Mn₂O₄ Na₄P₂O₇ S/ F/ Cl/ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Mo₂O₈ S/ F/ Cl/ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mn₃O₄/WO₄ S/ F/ Cl/ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Na₂WO₄ S/ F/ Cl/ Na₂WO₄ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ S/ F/ Cl/ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ NaMnO₄/MgO S/ F/ Cl/ NaMnO₄/MgO NaMnO₄/MgO NaMnO₄/MgO Na₁₀Mn—W₅O₁₇ S/ F/ Cl/ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ La₃NdO₆ S/ F/ Cl/ La₃NdO₆ La₃NdO₆ La₃NdO₆ LaNd₃O₆ S/ F/ Cl/ LaNd₃O₆ LaNd₃O₆ LaNd₃O₆ La_(1,5)Nd_(2,5)O₆ S/ F/ Cl/ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(2,5)Nd_(1,5)O₆ S/ F/ Cl/ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(3,2)Nd_(0,8)O₆ S/ F/ Cl/ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,5)Nd_(0,5)O₆ S/ F/ Cl/ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,8)Nd_(0,2)O₆ S/ F/ Cl/ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ Y—La S/ F/ Cl/ Y—La Y—La Y—La Zr—La S/ F/ Cl/ Zr—La Zr—La Zr—La Pr—La S/ F/ Cl/ Pr—La Pr—La Pr—La Ce—La S/ F/ Cl/ Ce—La Ce—La Ce—La

TABLE 3 NANOWIRES (NW) DOPED WITH SPECIFIC DOPANTS (DOP) Dop NW La Ce Pr Nd Li₂O La/ Ce/ Pr/ Nd/ Li₂O Li₂O Li₂O Li₂O Na₂O La/ Ce/ Pr/ Nd/ Na₂O Na₂O Na₂O Na₂O K₂O La/ Ce/ Pr/ Nd/ K₂O K₂O K₂O K₂O Rb₂O La/ Ce/ Pr/ Nd/ Rb₂O Rb₂O Rb₂O Rb₂O Cs₂O La/ Ce/ Pr/ Nd/ Cs₂O Cs₂O Cs₂O Cs₂O BeO La/ Ce/ Pr/ Nd/ BeO BeO BeO BeO MgO La/ Ce/ Pr/ Nd/ MgO MgO MgO MgO CaO La/ Ce/ Pr/ Nd/ CaO CaO CaO CaO SrO La/ Ce/ Pr/ Nd/ SrO SrO SrO SrO BaO La/ Ce/ Pr/ Nd/ BaO BaO BaO BaO Sc₂O₃ La/ Ce/ Pr/ Nd/ Sc₂O₃ Sc₂O₃ Sc₂O₃ Sc₂O₃ Y₂O₃ La/ Ce/ Pr/ Nd/ Y₂O₃ Y₂O₃ Y₂O₃ Y₂O₃ La₂O₃ La/ Ce/ Pr/ Nd/ La₂O₃ La₂O₃ La₂O₃ La₂O₃ CeO₂ La/ Ce/ Pr/ Nd/ CeO₂ CeO₂ CeO₂ CeO₂ Ce₂O₃ La/ Ce/ Pr/ Nd/ Ce₂O₃ Ce₂O₃ Ce₂O₃ Ce₂O₃ Pr₂O₃ La/ Ce/ Pr/ Nd/ Pr₂O₃ Pr₂O₃ Pr₂O₃ Pr₂O₃ Nd₂O₃ La/ Ce/ Pr/ Nd/ Nd₂O₃ Nd₂O₃ Nd₂O₃ Nd₂O₃ Sm₂O₃ La/ Ce/ Pr/ Nd/ Sm₂O₃ Sm₂O₃ Sm₂O₃ Sm₂O₃ Eu₂O₃ La/ Ce/ Pr/ Nd/ Eu₂O₃ Eu₂O₃ Eu₂O₃ Eu₂O₃ Gd₂O₃ La/ Ce/ Pr/ Nd/ Gd₂O₃ Gd₂O₃ Gd₂O₃ Gd₂O₃ Tb₂O₃ La/ Ce/ Pr/ Nd/ Tb₂O₃ Tb₂O₃ Tb₂O₃ Tb₂O₃ TbO₂ La/ Ce/ Pr/ Nd/ TbO₂ TbO₂ TbO₂ TbO₂ Tb₆O₁₁ La/ Ce/ Pr/ Nd/ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Dy₂O₃ La/ Ce/ Pr/ Nd/ Dy₂O₃ Dy₂O₃ Dy₂O₃ Dy₂O₃ Ho₂O₃ La/ Ce/ Pr/ Nd/ Ho₂O₃ Ho₂O₃ Ho₂O₃ Ho₂O₃ Er₂O₃ La/ Ce/ Pr/ Nd/ Er₂O₃ Er₂O₃ Er₂O₃ Er₂O₃ Tm₂O₃ La/ Ce/ Pr/ Nd/ Tm₂O₃ Tm₂O₃ Tm₂O₃ Tm₂O₃ Yb₂O₃ La/ Ce/ Pr/ Nd/ Yb₂O₃ Yb₂O₃ Yb₂O₃ Yb₂O₃ Lu₂O₃ La/ Ce/ Pr/ Nd/ Lu₂O₃ Lu₂O₃ Lu₂O₃ Lu₂O₃ Ac₂O₃ La/ Ce/ Pr/ Nd/ Ac₂O₃ Ac₂O₃ Ac₂O₃ Ac₂O₃ Th₂O₃ La/ Ce/ Pr/ Nd/ Th₂O₃ Th₂O₃ Th₂O₃ Th₂O₃ ThO₂ La/ Ce/ Pr/ Nd/ ThO₂ ThO₂ ThO₂ ThO₂ Pa₂O₃ La/ Ce/ Pr/ Nd/ Pa₂O₃ Pa₂O₃ Pa₂O₃ Pa₂O₃ PaO₂ La/ Ce/ Pr/ Nd/ PaO₂ PaO₂ PaO₂ PaO₂ TiO₂ La/ Ce/ Pr/ Nd/ TiO₂ TiO₂ TiO₂ TiO₂ TiO La/ Ce/ Pr/ Nd/ TiO TiO TiO TiO Ti₂O₃ La/ Ce/ Pr/ Nd/ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₃O La/ Ce/ Pr/ Nd/ Ti₃O Ti₃O Ti₃O Ti₃O Ti₂O La/ Ce/ Pr/ Nd/ Ti₂O Ti₂O Ti₂O Ti₂O Ti₃O₅ La/ Ce/ Pr/ Nd/ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₄O₇ La/ Ce/ Pr/ Nd/ Ti₄O₇ Ti₄O₇ Ti₄O₇ Ti₄O₇ ZrO₂ La/ Ce/ Pr/ Nd/ ZrO₂ ZrO₂ ZrO₂ ZrO₂ HfO₂ La/ Ce/ Pr/ Nd/ HfO₂ HfO₂ HfO₂ HfO₂ VO La/ Ce/ Pr/ Nd/ VO VO VO VO V₂O₃ La/ Ce/ Pr/ Nd/ V₂O₃ V₂O₃ V₂O₃ V₂O₃ VO₂ La/ Ce/ Pr/ Nd/ VO₂ VO₂ VO₂ VO₂ V₂O₅ La/ Ce/ Pr/ Nd/ V₂O₅ V₂O₅ V₂O₅ V₂O₅ V₃O₇ La/ Ce/ Pr/ Nd/ V₃O₇ V₃O₇ V₃O₇ V₃O₇ V₄O₉ La/ Ce/ Pr/ Nd/ V₄O₉ V₄O₉ V₄O₉ V₄O₉ V₆O₁₃ La/ Ce/ Pr/ Nd/ V₆O₁₃ V₆O₁₃ V₆O₁₃ V₆O₁₃ NbO La/ Ce/ Pr/ Nd/ NbO NbO NbO NbO NbO₂ La/ Ce/ Pr/ Nd/ NbO₂ NbO₂ NbO₂ NbO₂ Nb₂O₅ La/ Ce/ Pr/ Nd/ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₈O₁₉ La/ Ce/ Pr/ Nd/ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ La/ Ce/ Pr/ Nd/ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₂O₂₉ La/ Ce/ Pr/ Nd/ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₄₇O₁₁₆ La/ Ce/ Pr/ Nd/ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Ta₂O₅ La/ Ce/ Pr/ Nd/ Ta₂O₅ Ta₂O₅ Ta₂O₅ Ta₂O₅ CrO La/ Ce/ Pr/ Nd/ CrO CrO CrO CrO Cr₂O₃ La/ Ce/ Pr/ Nd/ Cr₂O₃ Cr₂O₃ Cr₂O₃ Cr₂O₃ CrO₂ La/ Ce/ Pr/ Nd/ CrO₂ CrO₂ CrO₂ CrO₂ CrO₃ La/ Ce/ Pr/ Nd/ CrO₃ CrO₃ CrO₃ CrO₃ Cr₈O₂₁ La/ Ce/ Pr/ Nd/ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ MoO₂ La/ Ce/ Pr/ Nd/ MoO₂ MoO₂ MoO₂ MoO₂ MoO₃ La/ Ce/ Pr/ Nd/ MoO₃ MoO₃ MoO₃ MoO₃ W₂O₃ La/ Ce/ Pr/ Nd/ W₂O₃ W₂O₃ W₂O₃ W₂O₃ WoO₂ La/ Ce/ Pr/ Nd/ WoO₂ WoO₂ WoO₂ WoO₂ WoO₃ La/ Ce/ Pr/ Nd/ WoO₃ WoO₃ WoO₃ WoO₃ MnO La/ Ce/ Pr/ Nd/ MnO MnO MnO MnO Mn/Mg/O La/ Ce/ Pr/ Nd/ Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn₃O₄ La/ Ce/ Pr/ Nd/ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₂O₃ La/ Ce/ Pr/ Nd/ Mn₂O₃ Mn₂O₃ Mn₂O₃ Mn₂O₃ MnO₂ La/ Ce/ Pr/ Nd/ MnO₂ MnO₂ MnO₂ MnO₂ Mn₂O₇ La/ Ce/ Pr/ Nd/ Mn₂O₇ Mn₂O₇ Mn₂O₇ Mn₂O₇ ReO₂ La/ Ce/ Pr/ Nd/ ReO₂ ReO₂ ReO₂ ReO₂ ReO₃ La/ Ce/ Pr/ Nd/ ReO₃ ReO₃ ReO₃ ReO₃ Re₂O₇ La/ Ce/ Pr/ Nd/ Re₂O₇ Re₂O₇ Re₂O₇ Re₂O₇ Mg₃Mn₃—B₂O₁₀ La/ Ce/ Pr/ Nd/ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂ La/ Ce/ Pr/ Nd/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ NaWO₄ La/ Ce/ Pr/ Nd/ NaWO₄ NaWO₄ NaWO₄ NaWO₄ Mg₆MnO₈ La/ Ce/ Pr/ Nd/ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ (Li,Mg)₆MnO₈ La/ Ce/ Pr/ Nd/ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ Mn₂O₄ La/ Ce/ Pr/ Nd/ Mn₂O₄ Mn₂O₄ Mn₂O₄ Mn₂O₄ Na₄P₂O₇ La/ Ce/ Pr/ Nd/ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Mo₂O₈ La/ Ce/ Pr/ Nd/ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mn₃O₄/WO₄ La/ Ce/ Pr/ Nd/ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Na₂WO₄ La/ Ce/ Pr/ Nd/ Na₂WO₄ Na₂WO₄ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ La/ Ce/ Pr/ Nd/ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ NaMnO₄−/ La/ Ce/ Pr/ Nd/ MgO NaMnO₄−/ NaMnO₄−/ NaMnO₄−/ NaMnO₄−/ MgO MgO MgO MgO Na₁₀Mn—W₅O₁₇ La/ Ce/ Pr/ Nd/ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ La₃NdO₆ La/ Ce/ Pr/ Nd/ La₃NdO₆ La₃NdO₆ La₃NdO₆ La₃NdO₆ LaNd₃O₆ La/ Ce/ Pr/ Nd/ LaNd₃O₆ LaNd₃O₆ LaNd₃O₆ LaNd₃O₆ La_(1,5)Nd_(2,5)O₆ La/ Ce/ Pr/ Nd/ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(2,5)Nd_(1,5)O₆ La/ Ce/ Pr/ Nd/ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(3,2)Nd_(0,8)O₆ La/ Ce/ Pr/ Nd/ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,5)Nd_(0,5)O₆ La/ Ce/ Pr/ Nd/ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,8)Nd_(0,2)O₆ La/ Ce/ Pr/ Nd/ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ Y—La La/ Ce/ Pr/ Nd/ Y—La Y—La Y—La Y—La Zr—La La/ Ce/ Pr/ Nd/ Zr—La Zr—La Zr—La Zr—La Pr—La La/ Ce/ Pr/ Nd/ Pr—La Pr—La Pr—La Pr—La Ce—La La/ Ce/ Pr/ Nd/ Ce—La Ce—La Ce—La Ce—La Dop NW Pm Sm Eu Gd Li₂O Pm/ Sm/ Eu/ Gd/ Li₂O Li₂O Li₂O Li₂O Na₂O Pm/ Sm/ Eu/ Gd/ Na₂O Na₂O Na₂O Na₂O K₂O Pm/ Sm/ Eu/ Gd/ K₂O K₂O K₂O K₂O Rb₂O Pm/ Sm/ Eu/ Gd/ Rb₂O Rb₂O Rb₂O Rb₂O Cs₂O Pm/ Sm/ Eu/ Gd/ Cs₂O Cs₂O Cs₂O Cs₂O BeO Pm/ Sm/ Eu/ Gd/ BeO BeO BeO BeO MgO Pm/ Sm/ Eu/ Gd/ MgO MgO MgO MgO CaO Pm/ Sm/ Eu/ Gd/ CaO CaO CaO CaO SrO Pm/ Sm/ Eu/ Gd/ SrO SrO SrO SrO BaO Pm/ Sm/ Eu/ Gd/ BaO BaO BaO BaO Sc₂O₃ Pm/ Sm/ Eu/ Gd/ Sc₂O₃ Sc₂O₃ Sc₂O₃ Sc₂O₃ Y₂O₃ Pm/ Sm/ Eu/ Gd/ Y₂O₃ Y₂O₃ Y₂O₃ Y₂O₃ La₂O₃ Pm/ Sm/ Eu/ Gd/ La₂O₃ La₂O₃ La₂O₃ La₂O₃ CeO₂ Pm/ Sm/ Eu/ Gd/ CeO₂ CeO₂ CeO₂ CeO₂ Ce₂O₃ Pm/ Sm/ Eu/ Gd/ Ce₂O₃ Ce₂O₃ Ce₂O₃ Ce₂O₃ Pr₂O₃ Pm/ Sm/ Eu/ Gd/ Pr₂O₃ Pr₂O₃ Pr₂O₃ Pr₂O₃ Nd₂O₃ Pm/ Sm/ Eu/ Gd/ Nd₂O₃ Nd₂O₃ Nd₂O₃ Nd₂O₃ Sm₂O₃ Pm/ Sm/ Eu/ Gd/ Sm₂O₃ Sm₂O₃ Sm₂O₃ Sm₂O₃ Eu₂O₃ Pm/ Sm/ Eu/ Gd/ Eu₂O₃ Eu₂O₃ Eu₂O₃ Eu₂O₃ Gd₂O₃ Pm/ Sm/ Eu/ Gd/ Gd₂O₃ Gd₂O₃ Gd₂O₃ Gd₂O₃ Tb₂O₃ Pm/ Sm/ Eu/ Gd/ Tb₂O₃ Tb₂O₃ Tb₂O₃ Tb₂O₃ TbO₂ Pm/ Sm/ Eu/ Gd/ TbO₂ TbO₂ TbO₂ TbO₂ Tb₆O₁₁ Pm/ Sm/ Eu/ Gd/ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Dy₂O₃ Pm/ Sm/ Eu/ Gd/ Dy₂O₃ Dy₂O₃ Dy₂O₃ Dy₂O₃ Ho₂O₃ Pm/ Sm/ Eu/ Gd/ Ho₂O₃ Ho₂O₃ Ho₂O₃ Ho₂O₃ Er₂O₃ Pm/ Sm/ Eu/ Gd/ Er₂O₃ Er₂O₃ Er₂O₃ Er₂O₃ Tm₂O₃ Pm/ Sm/ Eu/ Gd/ Tm₂O₃ Tm₂O₃ Tm₂O₃ Tm₂O₃ Yb₂O₃ Pm/ Sm/ Eu/ Gd/ Yb₂O₃ Yb₂O₃ Yb₂O₃ Yb₂O₃ Lu₂O₃ Pm/ Sm/ Eu/ Gd/ Lu₂O₃ Lu₂O₃ Lu₂O₃ Lu₂O₃ Ac₂O₃ Pm/ Sm/ Eu/ Gd/ Ac₂O₃ Ac₂O₃ Ac₂O₃ Ac₂O₃ Th₂O₃ Pm/ Sm/ Eu/ Gd/ Th₂O₃ Th₂O₃ Th₂O₃ Th₂O₃ ThO₂ Pm/ Sm/ Eu/ Gd/ ThO₂ ThO₂ ThO₂ ThO₂ Pa₂O₃ Pm/ Sm/ Eu/ Gd/ Pa₂O₃ Pa₂O₃ Pa₂O₃ Pa₂O₃ PaO₂ Pm/ Sm/ Eu/ Gd/ PaO₂ PaO₂ PaO₂ PaO₂ TiO₂ Pm/ Sm/ Eu/ Gd/ TiO₂ TiO₂ TiO₂ TiO₂ TiO Pm/ Sm/ Eu/ Gd/ TiO TiO TiO TiO Ti₂O₃ Pm/ Sm/ Eu/ Gd/ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₃O Pm/ Sm/ Eu/ Gd/ Ti₃O Ti₃O Ti₃O Ti₃O Ti₂O Pm/ Sm/ Eu/ Gd/ Ti₂O Ti₂O Ti₂O Ti₂O Ti₃O₅ Pm/ Sm/ Eu/ Gd/ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₄O₇ Pm/ Sm/ Eu/ Gd/ Ti₄O₇ Ti₄O₇ Ti₄O₇ Ti₄O₇ ZrO₂ Pm/ Sm/ Eu/ Gd/ ZrO₂ ZrO₂ ZrO₂ ZrO₂ HfO₂ Pm/ Sm/ Eu/ Gd/ HfO₂ HfO₂ HfO₂ HfO₂ VO Pm/ Sm/ Eu/ Gd/ VO VO VO VO V₂O₃ Pm/ Sm/ Eu/ Gd/ V₂O₃ V₂O₃ V₂O₃ V₂O₃ VO₂ Pm/ Sm/ Eu/ Gd/ VO₂ VO₂ VO₂ VO₂ V₂O₅ Pm/ Sm/ Eu/ Gd/ V₂O₅ V₂O₅ V₂O₅ V₂O₅ V₃O₇ Pm/ Sm/ Eu/ Gd/ V₃O₇ V₃O₇ V₃O₇ V₃O₇ V₄O₉ Pm/ Sm/ Eu/ Gd/ V₄O₉ V₄O₉ V₄O₉ V₄O₉ V₆O₁₃ Pm/ Sm/ Eu/ Gd/ V₆O₁₃ V₆O₁₃ V₆O₁₃ V₆O₁₃ NbO Pm/ Sm/ Eu/ Gd/ NbO NbO NbO NbO NbO₂ Pm/ Sm/ Eu/ Gd/ NbO₂ NbO₂ NbO₂ NbO₂ Nb₂O₅ Pm/ Sm/ Eu/ Gd/ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₈O₁₉ Pm/ Sm/ Eu/ Gd/ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ Pm/ Sm/ Eu/ Gd/ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₂O₂₉ Pm/ Sm/ Eu/ Gd/ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₄₇O₁₁₆ Pm/ Sm/ Eu/ Gd/ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Ta₂O₅ Pm/ Sm/ Eu/ Gd/ Ta₂O₅ Ta₂O₅ Ta₂O₅ Ta₂O₅ CrO Pm/ Sm/ Eu/ Gd/ CrO CrO CrO CrO Cr₂O₃ Pm/ Sm/ Eu/ Gd/ Cr₂O₃ Cr₂O₃ Cr₂O₃ Cr₂O₃ CrO₂ Pm/ Sm/ Eu/ Gd/ CrO₂ CrO₂ CrO₂ CrO₂ CrO₃ Pm/ Sm/ Eu/ Gd/ CrO₃ CrO₃ CrO₃ CrO₃ Cr₈O₂₁ Pm/ Sm/ Eu/ Gd/ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ MoO₂ Pm/ Sm/ Eu/ Gd/ MoO₂ MoO₂ MoO₂ MoO₂ MoO₃ Pm/ Sm/ Eu/ Gd/ MoO₃ MoO₃ MoO₃ MoO₃ W₂O₃ Pm/ Sm/ Eu/ Gd/ W₂O₃ W₂O₃ W₂O₃ W₂O₃ WoO₂ Pm/ Sm/ Eu/ Gd/ WoO₂ WoO₂ WoO₂ WoO₂ WoO₃ Pm/ Sm/ Eu/ Gd/ WoO₃ WoO₃ WoO₃ WoO₃ MnO Pm/ Sm/ Eu/ Gd/ MnO MnO MnO MnO Mn/Mg/O Pm/ Sm/ Eu/ Gd/ Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn₃O₄ Pm/ Sm/ Eu/ Gd/ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₂O₃ Pm/ Sm/ Eu/ Gd/ Mn₂O₃ Mn₂O₃ Mn₂O₃ Mn₂O₃ MnO₂ Pm/ Sm/ Eu/ Gd/ MnO₂ MnO₂ MnO₂ MnO₂ Mn₂O₇ Pm/ Sm/ Eu/ Gd/ Mn₂O₇ Mn₂O₇ Mn₂O₇ Mn₂O₇ ReO₂ Pm/ Sm/ Eu/ Gd/ ReO₂ ReO₂ ReO₂ ReO₂ ReO₃ Pm/ Sm/ Eu/ Gd/ ReO₃ ReO₃ ReO₃ ReO₃ Re₂O₇ Pm/ Sm/ Eu/ Gd/ Re₂O₇ Re₂O₇ Re₂O₇ Re₂O₇ Mg₃Mn₃—B₂O₁₀ Pm/ Sm/ Eu/ Gd/ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂ Pm/ Sm/ Eu/ Gd/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ NaWO₄ Pm/ Sm/ Eu/ Gd/ NaWO₄ NaWO₄ NaWO₄ NaWO₄ Mg₆MnO₈ Pm/ Sm/ Eu/ Gd/ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ (Li,Mg)₆MnO₈ Pm/ Sm/ Eu/ Gd/ (Li,Mg)₆MnO8 (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ Mn₂O₄ Pm/ Sm/ Eu/ Gd/ Mn₂O₄ Mn₂O₄ Mn₂O₄ Mn₂O₄ Na₄P₂O₇ Pm/ Sm/ Eu/ Gd/ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Mo₂O₈ Pm/ Sm/ Eu/ Gd/ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mn₃O₄/WO₄ Pm/ Sm/ Eu/ Gd/ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Na₂WO₄ Pm/ Sm/ Eu/ Gd/ Na₂WO₄ Na₂WO₄ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ Pm/ Sm/ Eu/ Gd/ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ NaMnO₄−/ Pm/ Sm/ Eu/ Gd/ MgO NaMnO₄−/ NaMnO₄−/ NaMnO₄−/ NaMnO₄−/ MgO MgO MgO MgO Na₁₀Mn—W₅O₁₇ Pm/ Sm/ Eu/ Gd/ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ La₃NdO₆ Pm/ Sm/ Eu/ Gd/ La₃NdO₆ La₃NdO₆ La₃NdO₆ La₃NdO₆ LaNd₃O₆ Pm/ Sm/ Eu/ Gd/ LaNd₃O₆ LaNd₃O₆ LaNd₃O₆ LaNd₃O₆ La_(1,5)Nd_(2,5)O₆ Pm/ Sm/ Eu/ Gd/ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(2,5)Nd_(1,5)O₆ Pm/ Sm/ Eu/ Gd/ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(3,2)Nd_(0,8)O₆ Pm/ Sm/ Eu/ Gd/ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,5)Nd_(0,5)O₆ Pm/ Sm/ Eu/ Gd/ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,8)Nd_(0,2)O₆ Pm/ Sm/ Eu/ Gd/ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ Y—La Pm/ Sm/ Eu/ Gd/ Y—La Y—La Y—La Y—La Zr—La Pm/ Sm/ Eu/ Gd/ Zr—La Zr—La Zr—La Zr—La Pr—La Pm/ Sm/ Eu/ Gd/ Pr—La Pr—La Pr—La Pr—La Ce—La Pm/ Sm/ Eu/ Gd/ Ce—La Ce—La Ce—La Ce—La

TABLE 4 NANOWIRES (NW) DOPED WITH SPECIFIC DOPANTS (DOP) Dop NW Tb Dy Ho Er Li₂O Tb/ Dy/ Ho/ Er/ Li₂O Li₂O Li₂O Li₂O Na₂O Tb/ Dy/ Ho/ Er/ Na₂O Na₂O Na₂O Na₂O K₂O Tb/ Dy/ Ho/ Er/ K₂O K₂O K₂O K₂O Rb₂O Tb/ Dy/ Ho/ Er/ Rb₂O Rb₂O Rb₂O Rb₂O Cs₂O Tb/ Dy/ Ho/ Er/ Cs₂O Cs₂O Cs₂O Cs₂O BeO Tb/ Dy/ Ho/ Er/ BeO BeO BeO BeO MgO Tb/ Dy/ Ho/ Er/ MgO MgO MgO MgO CaO Tb/ Dy/ Ho/ Er/ CaO CaO CaO CaO SrO Tb/ Dy/ Ho/ Er/ SrO SrO SrO SrO BaO Tb/ Dy/ Ho/ Er/ BaO BaO BaO BaO Sc₂O₃ Tb/ Dy/ Ho/ Er/ Sc₂O₃ Sc₂O₃ Sc₂O₃ Sc₂O₃ Y₂O₃ Tb/ Dy/ Ho/ Er/ Y₂O₃ Y₂O₃ Y₂O₃ Y₂O₃ La₂O₃ Tb/ Dy/ Ho/ Er/ La₂O₃ La₂O₃ La₂O₃ La₂O₃ CeO₂ Tb/ Dy/ Ho/ Er/ CeO₂ CeO₂ CeO₂ CeO₂ Ce₂O₃ Tb/ Dy/ Ho/ Er/ Ce₂O₃ Ce₂O₃ Ce₂O₃ Ce₂O₃ Pr₂O₃ Tb/ Dy/ Ho/ Er/ Pr₂O₃ Pr₂O₃ Pr₂O₃ Pr₂O₃ Nd₂O₃ Tb/ Dy/ Ho/ Er/ Nd₂O₃ Nd₂O₃ Nd₂O₃ Nd₂O₃ Sm₂O₃ Tb/ Dy/ Ho/ Er/ Sm₂O₃ Sm₂O₃ Sm₂O₃ Sm₂O₃ Eu₂O₃ Tb/ Dy/ Ho/ Er/ Eu₂O₃ Eu₂O₃ Eu₂O₃ Eu₂O₃ Gd₂O₃ Tb/ Dy/ Ho/ Er/ Gd₂O₃ Gd₂O₃ Gd₂O₃ Gd₂O₃ Tb₂O₃ Tb/ Dy/ Ho/ Er/ Tb₂O₃ Tb₂O₃ Tb₂O₃ Tb₂O₃ TbO₂ Tb/ Dy/ Ho/ Er/ TbO₂ TbO₂ TbO₂ TbO₂ Tb₆O₁₁ Tb/ Dy/ Ho/ Er/ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Dy₂O₃ Tb/ Dy/ Ho/ Er/ Dy₂O₃ Dy₂O₃ Dy₂O₃ Dy₂O₃ Ho₂O₃ Tb/ Dy/ Ho/ Er/ Ho₂O₃ Ho₂O₃ Ho₂O₃ Ho₂O₃ Er₂O₃ Tb/ Dy/ Ho/ Er/ Er₂O₃ Er₂O₃ Er₂O₃ Er₂O₃ Tm₂O₃ Tb/ Dy/ Ho/ Er/ Tm₂O₃ Tm₂O₃ Tm₂O₃ Tm₂O₃ Yb₂O₃ Tb/ Dy/ Ho/ Er/ Yb₂O₃ Yb₂O₃ Yb₂O₃ Yb₂O₃ Lu₂O₃ Tb/ Dy/ Ho/ Er/ Lu₂O₃ Lu₂O₃ Lu₂O₃ Lu₂O₃ Ac₂O₃ Tb/ Dy/ Ho/ Er/ Ac₂O₃ Ac₂O₃ Ac₂O₃ Ac₂O₃ Th₂O₃ Tb/ Dy/ Ho/ Er/ Th₂O₃ Th₂O₃ Th₂O₃ Th₂O₃ ThO₂ Tb/ Dy/ Ho/ Er/ ThO₂ ThO₂ ThO₂ ThO₂ Pa₂O₃ Tb/ Dy/ Ho/ Er/ Pa₂O₃ Pa₂O₃ Pa₂O₃ Pa₂O₃ PaO₂ Tb/ Dy/ Ho/ Er/ PaO₂ PaO₂ PaO₂ PaO₂ TiO₂ Tb/ Dy/ Ho/ Er/ TiO₂ TiO₂ TiO₂ TiO₂ TiO Tb/ Dy/ Ho/ Er/ TiO TiO TiO TiO Ti₂O₃ Tb/ Dy/ Ho/ Er/ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₃O Tb/ Dy/ Ho/ Er/ Ti₃O Ti₃O Ti₃O Ti₃O Ti₂O Tb/ Dy/ Ho/ Er/ Ti₂O Ti₂O Ti₂O Ti₂O Ti₃O₅ Tb/ Dy/ Ho/ Er/ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₄O₇ Tb/ Dy/ Ho/ Er/ Ti₄O₇ Ti₄O₇ Ti₄O₇ Ti₄O₇ ZrO₂ Tb/ Dy/ Ho/ Er/ ZrO₂ ZrO₂ ZrO₂ ZrO₂ HfO₂ Tb/ Dy/ Ho/ Er/ HfO₂ HfO₂ HfO₂ HfO₂ VO Tb/ Dy/ Ho/ Er/ VO VO VO VO V₂O₃ Tb/ Dy/ Ho/ Er/ V₂O₃ V₂O₃ V₂O₃ V₂O₃ VO₂ Tb/ Dy/ Ho/ Er/ VO₂ VO₂ VO₂ VO₂ V₂O₅ Tb/ Dy/ Ho/ Er/ V₂O₅ V₂O₅ V₂O₅ V₂O₅ V₃O₇ Tb/ Dy/ Ho/ Er/ V₃O₇ V₃O₇ V₃O₇ V₃O₇ V₄O₉ Tb/ Dy/ Ho/ Er/ V₄O₉ V₄O₉ V₄O₉ V₄O₉ V₆O₁₃ Tb/ Dy/ Ho/ Er/ V₆O₁₃ V₆O₁₃ V₆O₁₃ V₆O₁₃ NbO Tb/ Dy/ Ho/ Er/ NbO NbO NbO NbO NbO₂ Tb/ Dy/ Ho/ Er/ NbO₂ NbO₂ NbO₂ NbO₂ Nb₂O₅ Tb/ Dy/ Ho/ Er/ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₈O₁₉ Tb/ Dy/ Ho/ Er/ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ Tb/ Dy/ Ho/ Er/ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₂O₂₉ Tb/ Dy/ Ho/ Er/ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₄₇O₁₁₆ Tb/ Dy/ Ho/ Er/ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Ta₂O₅ Tb/ Dy/ Ho/ Er/ Ta₂O₅ Ta₂O₅ Ta₂O₅ Ta₂O₅ CrO Tb/ Dy/ Ho/ Er/ CrO CrO CrO CrO Cr₂O₃ Tb/ Dy/ Ho/ Er/ Cr₂O₃ Cr₂O₃ Cr₂O₃ Cr₂O₃ CrO₂ Tb/ Dy/ Ho/ Er/ CrO₂ CrO₂ CrO₂ CrO₂ CrO₃ Tb/ Dy/ Ho/ Er/ CrO₃ CrO₃ CrO₃ CrO₃ Cr₈O₂₁ Tb/ Dy/ Ho/ Er/ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ MoO₂ Tb/ Dy/ Ho/ Er/ MoO₂ MoO₂ MoO₂ MoO₂ MoO₃ Tb/ Dy/ Ho/ Er/ MoO₃ MoO₃ MoO₃ MoO₃ W₂O₃ Tb/ Dy/ Ho/ Er/ W₂O₃ W₂O₃ W₂O₃ W₂O₃ WoO₂ Tb/ Dy/ Ho/ Er/ WoO₂ WoO₂ WoO₂ WoO₂ WoO₃ Tb/ Dy/ Ho/ Er/ WoO₃ WoO₃ WoO₃ WoO₃ MnO Tb/ Dy/ Ho/ Er/ MnO MnO MnO MnO Mn/Mg/O Tb/ Dy/ Ho/ Er/ Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn₃O₄ Tb/ Dy/ Ho/ Er/ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₂O₃ Tb/ Dy/ Ho/ Er/ Mn₂O₃ Mn₂O₃ Mn₂O₃ Mn₂O₃ MnO₂ Tb/ Dy/ Ho/ Er/ MnO₂ MnO₂ MnO₂ MnO₂ Mn₂O₇ Tb/ Dy/ Ho/ Er/ Mn₂O₇ Mn₂O₇ Mn₂O₇ Mn₂O₇ ReO₂ Tb/ Dy/ Ho/ Er/ ReO₂ ReO₂ ReO₂ ReO₂ ReO₃ Tb/ Dy/ Ho/ Er/ ReO₃ ReO₃ ReO₃ ReO₃ Re₂O₇ Tb/ Dy/ Ho/ Er/ Re₂O₇ Re₂O₇ Re₂O₇ Re₂O₇ Mg₃Mn₃—B₂O₁₀ Tb/ Dy/ Ho/ Er/ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂ Tb/ Dy/ Ho/ Er/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ NaWO₄ Tb/ Dy/ Ho/ Er/ NaWO₄ NaWO₄ NaWO₄ NaWO₄ Mg₆MnO₈ Tb/ Dy/ Ho/ Er/ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mn₂O₄ Tb/ Dy/ Ho/ Er/ Mn₂O₄ Mn₂O₄ Mn₂O₄ Mn₂O₄ (Li,Mg)₆MnO₈ Tb/ Dy/ Ho/ Er/ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ Na₄P₂O₇ Tb/ Dy/ Ho/ Er/ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Mo₂O₈ Tb/ Dy/ Ho/ Er/ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mn₃O₄/WO₄ Tb/ Dy/ Ho/ Er/ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Na₂WO₄ Tb/ Dy/ Ho/ Er/ Na₂WO₄ Na₂WO₄ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ Tb/ Dy/ Ho/ Er/ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ NaMnO₄−/ Tb/ Dy/ Ho/ Er/ MgO NaMnO₄−/ NaMnO₄−/ NaMnO₄−/ NaMnO₄−/ MgO MgO MgO MgO Na₁₀Mn—W₅O₁₇ Tb/ Dy/ Ho/ Er/ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ La₃NdO₆ Tb/ Dy/ Ho/ Er/ La₃NdO₆ La₃NdO₆ La₃NdO₆ La₃NdO₆ LaNd₃O₆ Tb/ Dy/ Ho/ Er/ LaNd₃O₆ LaNd₃O₆ LaNd₃O₆ LaNd₃O₆ La_(1,5)Nd_(2,5)O₆ Tb/ Dy/ Ho/ Er/ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(2,5)Nd_(1,5)O₆ Tb/ Dy/ Ho/ Er/ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ Dop NW Tm Yb Lu In Li₂O Tm/ Yb/ Lu/ In/ Li₂O Li₂O Li₂O Li₂O Na₂O Tm/ Yb/ Lu/ In/ Na₂O Na₂O Na₂O Na₂O K₂O Tm/ Yb/ Lu/ In/ K₂O K₂O K₂O K₂O Rb₂O Tm/ Yb/ Lu/ In/ Rb₂O Rb₂O Rb₂O Rb₂O Cs₂O Tm/ Yb/ Lu/ In/ Cs₂O Cs₂O Cs₂O Cs₂O BeO Tm/ Yb/ Lu/ In/ BeO BeO BeO BeO MgO Tm/ Yb/ Lu/ In/ MgO MgO MgO MgO CaO Tm/ Yb/ Lu/ In/ CaO CaO CaO CaO SrO Tm/ Yb/ Lu/ In/ SrO SrO SrO SrO BaO Tm/ Yb/ Lu/ In/ BaO BaO BaO BaO Sc₂O₃ Tm/ Yb/ Lu/ In/ Sc₂O₃ Sc₂O₃ Sc₂O₃ Sc₂O₃ Y₂O₃ Tm/ Yb/ Lu/ In/ Y₂O₃ Y₂O₃ Y₂O₃ Y₂O₃ La₂O₃ Tm/ Yb/ Lu/ In/ La₂O₃ La₂O₃ La₂O₃ La₂O₃ CeO₂ Tm/ Yb/ Lu/ In/ CeO₂ CeO₂ CeO₂ CeO₂ Ce₂O₃ Tm/ Yb/ Lu/ In/ Ce₂O₃ Ce₂O₃ Ce₂O₃ Ce₂O₃ Pr₂O₃ Tm/ Yb/ Lu/ In/ Pr₂O₃ Pr₂O₃ Pr₂O₃ Pr₂O₃ Nd₂O₃ Tm/ Yb/ Lu/ In/ Nd₂O₃ Nd₂O₃ Nd₂O₃ Nd₂O₃ Sm₂O₃ Tm/ Yb/ Lu/ In/ Sm₂O₃ Sm₂O₃ Sm₂O₃ Sm₂O₃ Eu₂O₃ Tm/ Yb/ Lu/ In/ Eu₂O₃ Eu₂O₃ Eu₂O₃ Eu₂O₃ Gd₂O₃ Tm/ Yb/ Lu/ In/ Gd₂O₃ Gd₂O₃ Gd₂O₃ Gd₂O₃ Tb₂O₃ Tm/ Yb/ Lu/ In/ Tb₂O₃ Tb₂O₃ Tb₂O₃ Tb₂O₃ TbO₂ Tm/ Yb/ Lu/ In/ TbO₂ TbO₂ TbO₂ TbO₂ Tb₆O₁₁ Tm/ Yb/ Lu/ In/ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Dy₂O₃ Tm/ Yb/ Lu/ In/ Dy₂O₃ Dy₂O₃ Dy₂O₃ Dy₂O₃ Ho₂O₃ Tm/ Yb/ Lu/ In/ Ho₂O₃ Ho₂O₃ Ho₂O₃ Ho₂O₃ Er₂O₃ Tm/ Yb/ Lu/ In/ Er₂O₃ Er₂O₃ Er₂O₃ Er₂O₃ Tm₂O₃ Tm/ Yb/ Lu/ In/ Tm₂O₃ Tm₂O₃ Tm₂O₃ Tm₂O₃ Yb₂O₃ Tm/ Yb/ Lu/ In/ Yb₂O₃ Yb₂O₃ Yb₂O₃ Yb₂O₃ Lu₂O₃ Tm/ Yb/ Lu/ In/ Lu₂O₃ Lu₂O₃ Lu₂O₃ Lu₂O₃ Ac₂O₃ Tm/ Yb/ Lu/ In/ Ac₂O₃ Ac₂O₃ Ac₂O₃ Ac₂O₃ Th₂O₃ Tm/ Yb/ Lu/ In/ Th₂O₃ Th₂O₃ Th₂O₃ Th₂O₃ ThO₂ Tm/ Yb/ Lu/ In/ ThO₂ ThO₂ ThO₂ ThO₂ Pa₂O₃ Tm/ Yb/ Lu/ In/ Pa₂O₃ Pa₂O₃ Pa₂O₃ Pa₂O₃ PaO₂ Tm/ Yb/ Lu/ In/ PaO₂ PaO₂ PaO₂ PaO₂ TiO₂ Tm/ Yb/ Lu/ In/ TiO₂ TiO₂ TiO₂ TiO₂ TiO Tm/ Yb/ Lu/ In/ TiO TiO TiO TiO Ti₂O₃ Tm/ Yb/ Lu/ In/ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₃O Tm/ Yb/ Lu/ In/ Ti₃O Ti₃O Ti₃O Ti₃O Ti₂O Tm/ Yb/ Lu/ In/ Ti₂O Ti₂O Ti₂O Ti₂O Ti₃O₅ Tm/ Yb/ Lu/ In/ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₄O₇ Tm/ Yb/ Lu/ In/ Ti₄O₇ Ti₄O₇ Ti₄O₇ Ti₄O₇ ZrO₂ Tm/ Yb/ Lu/ In/ ZrO₂ ZrO₂ ZrO₂ ZrO₂ HfO₂ Tm/ Yb/ Lu/ In/ HfO₂ HfO₂ HfO₂ HfO₂ VO Tm/ Yb/ Lu/ In/ VO VO VO VO V₂O₃ Tm/ Yb/ Lu/ In/ V₂O₃ V₂O₃ V₂O₃ V₂O₃ VO₂ Tm/ Yb/ Lu/ In/ VO₂ VO₂ VO₂ VO₂ V₂O₅ Tm/ Yb/ Lu/ In/ V₂O₅ V₂O₅ V₂O₅ V₂O₅ V₃O₇ Tm/ Yb/ Lu/ In/ V₃O₇ V₃O₇ V₃O₇ V₃O₇ V₄O₉ Tm/ Yb/ Lu/ In/ V₄O₉ V₄O₉ V₄O₉ V₄O₉ V₆O₁₃ Tm/ Yb/ Lu/ In/ V₆O₁₃ V₆O₁₃ V₆O₁₃ V₆O₁₃ NbO Tm/ Yb/ Lu/ In/ NbO NbO NbO NbO NbO₂ Tm/ Yb/ Lu/ In/ NbO₂ NbO₂ NbO₂ NbO₂ Nb₂O₅ Tm/ Yb/ Lu/ In/ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₈O₁₉ Tm/ Yb/ Lu/ In/ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ Tm/ Yb/ Lu/ In/ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₂O₂₉ Tm/ Yb/ Lu/ In/ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₄₇O₁₁₆ Tm/ Yb/ Lu/ In/ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Ta₂O₅ Tm/ Yb/ Lu/ In/ Ta₂O₅ Ta₂O₅ Ta₂O₅ Ta₂O₅ CrO Tm/ Yb/ Lu/ In/ CrO CrO CrO CrO Cr₂O₃ Tm/ Yb/ Lu/ In/ Cr₂O₃ Cr₂O₃ Cr₂O₃ Cr₂O₃ CrO₂ Tm/ Yb/ Lu/ In/ CrO₂ CrO₂ CrO₂ CrO₂ CrO₃ Tm/ Yb/ Lu/ In/ CrO₃ CrO₃ CrO₃ CrO₃ Cr₈O₂₁ Tm/ Yb/ Lu/ In/ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ MoO₂ Tm/ Yb/ Lu/ In/ MoO₂ MoO₂ MoO₂ MoO₂ MoO₃ Tm/ Yb/ Lu/ In/ MoO₃ MoO₃ MoO₃ MoO₃ W₂O₃ Tm/ Yb/ Lu/ In/ W₂O₃ W₂O₃ W₂O₃ W₂O₃ WoO₂ Tm/ Yb/ Lu/ In/ WoO₂ WoO₂ WoO₂ WoO₂ WoO₃ Tm/ Yb/ Lu/ In/ WoO₃ WoO₃ WoO₃ WoO₃ MnO Tm/ Yb/ Lu/ In/ MnO MnO MnO MnO Mn/Mg/O Tm/ Yb/ Lu/ In/ Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn₃O₄ Tm/ Yb/ Lu/ In/ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₂O₃ Tm/ Yb/ Lu/ In/ Mn₂O₃ Mn₂O₃ Mn₂O₃ Mn₂O₃ MnO₂ Tm/ Yb/ Lu/ In/ MnO₂ MnO₂ MnO₂ MnO₂ Mn₂O₇ Tm/ Yb/ Lu/ In/ Mn₂O₇ Mn₂O₇ Mn₂O₇ Mn₂O₇ ReO₂ Tm/ Yb/ Lu/ In/ ReO₂ ReO₂ ReO₂ ReO₂ ReO₃ Tm/ Yb/ Lu/ In/ ReO₃ ReO₃ ReO₃ ReO₃ Re₂O₇ Tm/ Yb/ Lu/ In/ Re₂O₇ Re₂O₇ Re₂O₇ Re₂O₇ Mg₃Mn₃—B₂O₁₀ Tm/ Yb/ Lu/ In/ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂ Tm/ Yb/ Lu/ In/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ NaWO₄ Tm/ Yb/ Lu/ In/ NaWO₄ NaWO₄ NaWO₄ NaWO₄ Mg₆MnO₈ Tm/ Yb/ Lu/ In/ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mn₂O₄ Tm/ Yb/ Lu/ In/ Mn₂O₄ Mn₂O₄ Mn₂O₄ Mn₂O₄ (Li,Mg)₆MnO₈ Tm/ Yb/ Lu/ In/ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ Na₄P₂O₇ Tm/ Yb/ Lu/ In/ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Mo₂O₈ Tm/ Yb/ Lu/ In/ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mn₃O₄/WO₄ Tm/ Yb/ Lu/ In/ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Na₂WO₄ Tm/ Yb/ Lu/ In/ Na₂WO₄ Na₂WO₄ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ Tm/ Yb/ Lu/ In/ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ NaMnO₄−/ Tm/ Yb/ Lu/ In/ MgO NaMnO₄−/ NaMnO₄−/ NaMnO₄−/ NaMnO₄−/ MgO MgO MgO MgO Na₁₀Mn—W₅O₁₇ Tm/ Yb/ Lu/ In/ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ La₃NdO₆ Tm/ Yb/ Lu/ In/ La₃NdO₆ La₃NdO₆ La₃NdO₆ La₃NdO₆ LaNd₃O₆ Tm/ Yb/ Lu/ In/ LaNd₃O₆ LaNd₃O₆ LaNd₃O₆ LaNd₃O₆ La_(1,5)Nd_(2,5)O₆ Tm/ Yb/ Lu/ In/ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(2,5)Nd_(1,5)O₆ Tm/ Yb/ Lu/ In/ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆

TABLE 5 NANOWIRES (NW) DOPED WITH SPECIFIC DOPANTS (DOP) Dop NW Y Sc Al Cu Li₂O Y/ Sc/ Al/ Cu/ Li₂O Li₂O Li₂O Li₂O Na₂O Y/ Sc/ Al/ Cu/ Na₂O Na₂O Na₂O Na₂O K₂O Y/ Sc/ Al/ Cu/ K₂O K₂O K₂O K₂O Rb₂O Y/ Sc/ Al/ Cu/ Rb₂O Rb₂O Rb₂O Rb₂O Cs₂O Y/ Sc/ Al/ Cu/ Cs₂O Cs₂O Cs₂O Cs₂O BeO Y/ Sc/ Al/ Cu/ BeO BeO BeO BeO MgO Y/ Sc/ Al/ Cu/ MgO MgO MgO MgO CaO Y/ Sc/ Al/ Cu/ CaO CaO CaO CaO SrO Y/ Sc/ Al/ Cu/ SrO SrO SrO SrO BaO Y/ Sc/ Al/ Cu/ BaO BaO BaO BaO Sc₂O₃ Y/ Sc/ Al/ Cu/ Sc₂O₃ Sc₂O₃ Sc₂O₃ Sc₂O₃ Y₂O₃ Y/ Sc/ Al/ Cu/ Y₂O₃ Y₂O₃ Y₂O₃ Y₂O₃ La₂O₃ Y/ Sc/ Al/ Cu/ La₂O₃ La₂O₃ La₂O₃ La₂O₃ CeO₂ Y/ Sc/ Al/ Cu/ CeO₂ CeO₂ CeO₂ CeO₂ Ce₂O₃ Y/ Sc/ Al/ Cu/ Ce₂O₃ Ce₂O₃ Ce₂O₃ Ce₂O₃ Pr₂O₃ Y/ Sc/ Al/ Cu/ Pr₂O₃ Pr₂O₃ Pr₂O₃ Pr₂O₃ Nd₂O₃ Y/ Sc/ Al/ Cu/ Nd₂O₃ Nd₂O₃ Nd₂O₃ Nd₂O₃ Sm₂O₃ Y/ Sc/ Al/ Cu/ Sm₂O₃ Sm₂O₃ Sm₂O₃ Sm₂O₃ Eu₂O₃ Y/ Sc/ Al/ Cu/ Eu₂O₃ Eu₂O₃ Eu₂O₃ Eu₂O₃ Gd₂O₃ Y/ Sc/ Al/ Cu/ Gd₂O₃ Gd₂O₃ Gd₂O₃ Gd₂O₃ Tb₂O₃ Y/ Sc/ Al/ Cu/ Tb₂O₃ Tb₂O₃ Tb₂O₃ Tb₂O₃ TbO₂ Y/ Sc/ Al/ Cu/ TbO₂ TbO₂ TbO₂ TbO₂ Tb₆O₁₁ Y/ Sc/ Al/ Cu/ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Dy₂O₃ Y/ Sc/ Al/ Cu/ Dy₂O₃ Dy₂O₃ Dy₂O₃ Dy₂O₃ Ho₂O₃ Y/ Sc/ Al/ Cu/ Ho₂O₃ Ho₂O₃ Ho₂O₃ Ho₂O₃ Er₂O₃ Y/ Sc/ Al/ Cu/ Er₂O₃ Er₂O₃ Er₂O₃ Er₂O₃ Tm₂O₃ Y/ Sc/ Al/ Cu/ Tm₂O₃ Tm₂O₃ Tm₂O₃ Tm₂O₃ Yb₂O₃ Y/ Sc/ Al/ Cu/ Yb₂O₃ Yb₂O₃ Yb₂O₃ Yb₂O₃ Lu₂O₃ Y/ Sc/ Al/ Cu/ Lu₂O₃ Lu₂O₃ Lu₂O₃ Lu₂O₃ Ac₂O₃ Y/ Sc/ Al/ Cu/ Ac₂O₃ Ac₂O₃ Ac₂O₃ Ac₂O₃ Th₂O₃ Y/ Sc/ Al/ Cu/ Th₂O₃ Th₂O₃ Th₂O₃ Th₂O₃ ThO₂ Y/ Sc/ Al/ Cu/ ThO₂ ThO₂ ThO₂ ThO₂ Pa₂O₃ Y/ Sc/ Al/ Cu/ Pa₂O₃ Pa₂O₃ Pa₂O₃ Pa₂O₃ PaO₂ Y/ Sc/ Al/ Cu/ PaO₂ PaO₂ PaO₂ PaO₂ TiO₂ Y/ Sc/ Al/ Cu/ TiO₂ TiO₂ TiO₂ TiO₂ TiO Y/ Sc/ Al/ Cu/ TiO TiO TiO TiO Ti₂O₃ Y/ Sc/ Al/ Cu/ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₃O Y/ Sc/ Al/ Cu/ Ti₃O Ti₃O Ti₃O Ti₃O Ti₂O Y/ Sc/ Al/ Cu/ Ti₂O Ti₂O Ti₂O Ti₂O Ti₃O₅ Y/ Sc/ Al/ Cu/ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₄O₇ Y/ Sc/ Al/ Cu/ Ti₄O₇ Ti₄O₇ Ti₄O₇ Ti₄O₇ ZrO₂ Y/ Sc/ Al/ Cu/ ZrO₂ ZrO₂ ZrO₂ ZrO₂ HfO₂ Y/ Sc/ Al/ Cu/ HfO₂ HfO₂ HfO₂ HfO₂ VO Y/ Sc/ Al/ Cu/ VO VO VO VO V₂O₃ Y/ Sc/ Al/ Cu/ V₂O₃ V₂O₃ V₂O₃ V₂O₃ VO₂ Y/ Sc/ Al/ Cu/ VO₂ VO₂ VO₂ VO₂ V₂O₅ Y/ Sc/ Al/ Cu/ V₂O₅ V₂O₅ V₂O₅ V₂O₅ V₃O₇ Y/ Sc/ Al/ Cu/ V₃O₇ V₃O₇ V₃O₇ V₃O₇ V₄O₉ Y/ Sc/ Al/ Cu/ V₄O₉ V₄O₉ V₄O₉ V₄O₉ V₆O₁₃ Y/ Sc/ Al/ Cu/ V₆O₁₃ V₆O₁₃ V₆O₁₃ V₆O₁₃ NbO Y/ Sc/ Al/ Cu/ NbO NbO NbO NbO NbO₂ Y/ Sc/ Al/ Cu/ NbO₂ NbO₂ NbO₂ NbO₂ Nb₂O₅ Y/ Sc/ Al/ Cu/ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₈O₁₉ Y/ Sc/ Al/ Cu/ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ Y/ Sc/ Al/ Cu/ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₂O₂₉ Y/ Sc/ Al/ Cu/ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₄₇O₁₁₆ Y/ Sc/ Al/ Cu/ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Ta₂O₅ Y/ Sc/ Al/ Cu/ Ta₂O₅ Ta₂O₅ Ta₂O₅ Ta₂O₅ CrO Y/ Sc/ Al/ Cu/ CrO CrO CrO CrO Cr₂O₃ Y/ Sc/ Al/ Cu/ Cr₂O₃ Cr₂O₃ Cr₂O₃ Cr₂O₃ CrO₂ Y/ Sc/ Al/ Cu/ CrO₂ CrO₂ CrO₂ CrO₂ CrO₃ Y/ Sc/ Al/ Cu/ CrO₃ CrO₃ CrO₃ CrO₃ Cr₈O₂₁ Y/ Sc/ Al/ Cu/ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ MoO₂ Y/ Sc/ Al/ Cu/ MoO₂ MoO₂ MoO₂ MoO₂ MoO₃ Y/ Sc/ Al/ Cu/ MoO₃ MoO₃ MoO₃ MoO₃ W₂O₃ Y/ Sc/ Al/ Cu/ W₂O₃ W₂O₃ W₂O₃ W₂O₃ WoO₂ Y/ Sc/ Al/ Cu/ WoO₂ WoO₂ WoO₂ WoO₂ WoO₃ Y/ Sc/ Al/ Cu/ WoO₃ WoO₃ WoO₃ WoO₃ MnO Y/ Sc/ Al/ Cu/ MnO MnO MnO MnO Mn/Mg/O Y/ Sc/ Al/ Cu/ Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn₃O₄ Y/ Sc/ Al/ Cu/ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₂O₃ Y/ Sc/ Al/ Cu/ Mn₂O₃ Mn₂O₃ Mn₂O₃ Mn₂O₃ MnO₂ Y/ Sc/ Al/ Cu/ MnO₂ MnO₂ MnO₂ MnO₂ Mn₂O₇ Y/ Sc/ Al/ Cu/ Mn₂O₇ Mn₂O₇ Mn₂O₇ Mn₂O₇ ReO₂ Y/ Sc/ Al/ Cu/ ReO₂ ReO₂ ReO₂ ReO₂ ReO₃ Y/ Sc/ Al/ Cu/ ReO₃ ReO₃ ReO₃ ReO₃ Re₂O₇ Y/ Sc/ Al/ Cu/ Re₂O₇ Re₂O₇ Re₂O₇ Re₂O₇ Mg₃Mn₃—B₂O₁₀ Y/ Sc/ Al/ Cu/ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂ Y/ Sc/ Al/ Cu/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ NaWO₄ Y/ Sc/ Al/ Cu/ NaWO₄ NaWO₄ NaWO₄ NaWO₄ Mg₆MnO₈ Y/ Sc/ Al/ Cu/ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mn₂O₄ Y/ Sc/ Al/ Cu/ Mn₂O₄ Mn₂O₄ Mn₂O₄ Mn₂O₄ (Li,Mg)₆MnO₈ Y/ Sc/ Al/ Cu/ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ Na₄P₂O₇ Y/ Sc/ Al/ Cu/ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Mo₂O₈ Y/ Sc/ Al/ Cu/ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mn₃O₄/WO₄ Y/ Sc/ Al/ Cu/ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Na₂WO₄ Y/ Sc/ Al/ Cu/ Na₂WO₄ Na₂WO₄ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ Y/ Sc/ Al/ Cu/ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ NaMnO₄−/ Y/ Sc/ Al/ Cu/ MgO NaMnO₄−/ NaMnO₄−/ NaMnO₄−/ NaMnO₄−/ MgO MgO MgO MgO Na₁₀Mn—W₅O₁₇ Y/ Sc/ Al/ Cu/ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ La₃NdO₆ Y/ Sc/ Al/ Cu/ La₃NdO₆ La₃NdO₆ La₃NdO₆ La₃NdO₆ LaNd₃O₆ Y/ Sc/ Al/ Cu/ LaNd₃O₆ LaNd₃O₆ LaNd₃O₆ LaNd₃O₆ La_(1,5)Nd_(2,5)O₆ Y/ Sc/ Al/ Cu/ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(2,5)Nd_(1,5)O₆ Y/ Sc/ Al/ Cu/ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(3,2)Nd_(0,8)O₆ Y/ Sc/ Al/ Cu/ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,5)Nd_(0,5)O₆ Y/ Sc/ Al/ Cu/ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,8)Nd_(0,2)O₆ Y/ Sc/ Al/ Cu/ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ Y—La Y/ Sc/ Al/ Cu/ Y—La Y—La Y—La Y—La Zr—La Y/ Sc/ Al/ Cu/ Zr—La Zr—La Zr—La Zr—La Pr—La Y/ Sc/ Al/ Cu/ Pr—La Pr—La Pr—La Pr—La Ce—La Y/ Sc/ Al/ Cu/ Ce—La Ce—La Ce—La Ce—La Dop NW Ga Hf Fe Cr Li₂O Ga/ Hf/ Fe/ Cr/ Li₂O Li₂O Li₂O Li₂O Na₂O Ga/ Hf/ Fe/ Cr/ Na₂O Na₂O Na₂O Na₂O K₂O Ga/ Hf/ Fe/ Cr/ K₂O K₂O K₂O K₂O Rb₂O Ga/ Hf/ Fe/ Cr/ Rb₂O Rb₂O Rb₂O Rb₂O Cs₂O Ga/ Hf/ Fe/ Cr/ Cs₂O Cs₂O Cs₂O Cs₂O BeO Ga/ Hf/ Fe/ Cr/ BeO BeO BeO BeO MgO Ga/ Hf/ Fe/ Cr/ MgO MgO MgO MgO CaO Ga/ Hf/ Fe/ Cr/ CaO CaO CaO CaO SrO Ga/ Hf/ Fe/ Cr/ SrO SrO SrO SrO BaO Ga/ Hf/ Fe/ Cr/ BaO BaO BaO BaO Sc₂O₃ Ga/ Hf/ Fe/ Cr/ Sc₂O₃ Sc₂O₃ Sc₂O₃ Sc₂O₃ Y₂O₃ Ga/ Hf/ Fe/ Cr/ Y₂O₃ Y₂O₃ Y₂O₃ Y₂O₃ La₂O₃ Ga/ Hf/ Fe/ Cr/ La₂O₃ La₂O₃ La₂O₃ La₂O₃ CeO₂ Ga/ Hf/ Fe/ Cr/ CeO₂ CeO₂ CeO₂ CeO₂ Ce₂O₃ Ga/ Hf/ Fe/ Cr/ Ce₂O₃ Ce₂O₃ Ce₂O₃ Ce₂O₃ Pr₂O₃ Ga/ Hf/ Fe/ Cr/ Pr₂O₃ Pr₂O₃ Pr₂O₃ Pr₂O₃ Nd₂O₃ Ga/ Hf/ Fe/ Cr/ Nd₂O₃ Nd₂O₃ Nd₂O₃ Nd₂O₃ Sm₂O₃ Ga/ Hf/ Fe/ Cr/ Sm₂O₃ Sm₂O₃ Sm₂O₃ Sm₂O₃ Eu₂O₃ Ga/ Hf/ Fe/ Cr/ Eu₂O₃ Eu₂O₃ Eu₂O₃ Eu₂O₃ Gd₂O₃ Ga/ Hf/ Fe/ Cr/ Gd₂O₃ Gd₂O₃ Gd₂O₃ Gd₂O₃ Tb₂O₃ Ga/ Hf/ Fe/ Cr/ Tb₂O₃ Tb₂O₃ Tb₂O₃ Tb₂O₃ TbO₂ Ga/ Hf/ Fe/ Cr/ TbO₂ TbO₂ TbO₂ TbO₂ Tb₆O₁₁ Ga/ Hf/ Fe/ Cr/ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Dy₂O₃ Ga/ Hf/ Fe/ Cr/ Dy₂O₃ Dy₂O₃ Dy₂O₃ Dy₂O₃ Ho₂O₃ Ga/ Hf/ Fe/ Cr/ Ho₂O₃ Ho₂O₃ Ho₂O₃ Ho₂O₃ Er₂O₃ Ga/ Hf/ Fe/ Cr/ Er₂O₃ Er₂O₃ Er₂O₃ Er₂O₃ Tm₂O₃ Ga/ Hf/ Fe/ Cr/ Tm₂O₃ Tm₂O₃ Tm₂O₃ Tm₂O₃ Yb₂O₃ Ga/ Hf/ Fe/ Cr/ Yb₂O₃ Yb₂O₃ Yb₂O₃ Yb₂O₃ Lu₂O₃ Ga/ Hf/ Fe/ Cr/ Lu₂O₃ Lu₂O₃ Lu₂O₃ Lu₂O₃ Ac₂O₃ Ga/ Hf/ Fe/ Cr/ Ac₂O₃ Ac₂O₃ Ac₂O₃ Ac₂O₃ Th₂O₃ Ga/ Hf/ Fe/ Cr/ Th₂O₃ Th₂O₃ Th₂O₃ Th₂O₃ ThO₂ Ga/ Hf/ Fe/ Cr/ ThO₂ ThO₂ ThO₂ ThO₂ Pa₂O₃ Ga/ Hf/ Fe/ Cr/ Pa₂O₃ Pa₂O₃ Pa₂O₃ Pa₂O₃ PaO₂ Ga/ Hf/ Fe/ Cr/ PaO₂ PaO₂ PaO₂ PaO₂ TiO₂ Ga/ Hf/ Fe/ Cr/ TiO₂ TiO₂ TiO₂ TiO₂ TiO Ga/ Hf/ Fe/ Cr/ TiO TiO TiO TiO Ti₂O₃ Ga/ Hf/ Fe/ Cr/ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₃O Ga/ Hf/ Fe/ Cr/ Ti₃O Ti₃O Ti₃O Ti₃O Ti₂O Ga/ Hf/ Fe/ Cr/ Ti₂O Ti₂O Ti₂O Ti₂O Ti₃O₅ Ga/ Hf/ Fe/ Cr/ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₄O₇ Ga/ Hf/ Fe/ Cr/ Ti₄O₇ Ti₄O₇ Ti₄O₇ Ti₄O₇ ZrO₂ Ga/ Hf/ Fe/ Cr/ ZrO₂ ZrO₂ ZrO₂ ZrO₂ HfO₂ Ga/ Hf/ Fe/ Cr/ HfO₂ HfO₂ HfO₂ HfO₂ VO Ga/ Hf/ Fe/ Cr/ VO VO VO VO V₂O₃ Ga/ Hf/ Fe/ Cr/ V₂O₃ V₂O₃ V₂O₃ V₂O₃ VO₂ Ga/ Hf/ Fe/ Cr/ VO₂ VO₂ VO₂ VO₂ V₂O₅ Ga/ Hf/ Fe/ Cr/ V₂O₅ V₂O₅ V₂O₅ V₂O₅ V₃O₇ Ga/ Hf/ Fe/ Cr/ V₃O₇ V₃O₇ V₃O₇ V₃O₇ V₄O₉ Ga/ Hf/ Fe/ Cr/ V₄O₉ V₄O₉ V₄O₉ V₄O₉ V₆O₁₃ Ga/ Hf/ Fe/ Cr/ V₆O₁₃ V₆O₁₃ V₆O₁₃ V₆O₁₃ NbO Ga/ Hf/ Fe/ Cr/ NbO NbO NbO NbO NbO₂ Ga/ Hf/ Fe/ Cr/ NbO₂ NbO₂ NbO₂ NbO₂ Nb₂O₅ Ga/ Hf/ Fe/ Cr/ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₈O₁₉ Ga/ Hf/ Fe/ Cr/ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ Ga/ Hf/ Fe/ Cr/ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₂O₂₉ Ga/ Hf/ Fe/ Cr/ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₄₇O₁₁₆ Ga/ Hf/ Fe/ Cr/ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Ta₂O₅ Ga/ Hf/ Fe/ Cr/ Ta₂O₅ Ta₂O₅ Ta₂O₅ Ta₂O₅ CrO Ga/ Hf/ Fe/ Cr/ CrO CrO CrO CrO Cr₂O₃ Ga/ Hf/ Fe/ Cr/ Cr₂O₃ Cr₂O₃ Cr₂O₃ Cr₂O₃ CrO₂ Ga/ Hf/ Fe/ Cr/ CrO₂ CrO₂ CrO₂ CrO₂ CrO₃ Ga/ Hf/ Fe/ Cr/ CrO₃ CrO₃ CrO₃ CrO₃ Cr₈O₂₁ Ga/ Hf/ Fe/ Cr/ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ MoO₂ Ga/ Hf/ Fe/ Cr/ MoO₂ MoO₂ MoO₂ MoO₂ MoO₃ Ga/ Hf/ Fe/ Cr/ MoO₃ MoO₃ MoO₃ MoO₃ W₂O₃ Ga/ Hf/ Fe/ Cr/ W₂O₃ W₂O₃ W₂O₃ W₂O₃ WoO₂ Ga/ Hf/ Fe/ Cr/ WoO₂ WoO₂ WoO₂ WoO₂ WoO₃ Ga/ Hf/ Fe/ Cr/ WoO₃ WoO₃ WoO₃ WoO₃ MnO Ga/ Hf/ Fe/ Cr/ MnO MnO MnO MnO Mn/Mg/O Ga/ Hf/ Fe/ Cr/ Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn₃O₄ Ga/ Hf/ Fe/ Cr/ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₂O₃ Ga/ Hf/ Fe/ Cr/ Mn₂O₃ Mn₂O₃ Mn₂O₃ Mn₂O₃ MnO₂ Ga/ Hf/ Fe/ Cr/ MnO₂ MnO₂ MnO₂ MnO₂ Mn₂O₇ Ga/ Hf/ Fe/ Cr/ Mn₂O₇ Mn₂O₇ Mn₂O₇ Mn₂O₇ ReO₂ Ga/ Hf/ Fe/ Cr/ ReO₂ ReO₂ ReO₂ ReO₂ ReO₃ Ga/ Hf/ Fe/ Cr/ ReO₃ ReO₃ ReO₃ ReO₃ Re₂O₇ Ga/ Hf/ Fe/ Cr/ Re₂O₇ Re₂O₇ Re₂O₇ Re₂O₇ Mg₃Mn₃—B₂O₁₀ Ga/ Hf/ Fe/ Cr/ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂ Ga/ Hf/ Fe/ Cr/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ NaWO₄ Ga/ Hf/ Fe/ Cr/ NaWO₄ NaWO₄ NaWO₄ NaWO₄ Mg₆MnO₈ Ga/ Hf/ Fe/ Cr/ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mn₂O₄ Ga/ Hf/ Fe/ Cr/ Mn₂O₄ Mn₂O₄ Mn₂O₄ Mn₂O₄ (Li,Mg)₆MnO₈ Ga/ Hf/ Fe/ Cr/ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ Na₄P₂O₇ Ga/ Hf/ Fe/ Cr/ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Mo₂O₈ Ga/ Hf/ Fe/ Cr/ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mn₃O₄/WO₄ Ga/ Hf/ Fe/ Cr/ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Na₂WO₄ Ga/ Hf/ Fe/ Cr/ Na₂WO₄ Na₂WO₄ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ Ga/ Hf/ Fe/ Cr/ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ NaMnO₄−/ Ga/ Hf/ Fe/ Cr/ MgO NaMnO₄−/ NaMnO₄−/ NaMnO₄−/ NaMnO₄−/ MgO MgO MgO MgO Na₁₀Mn—W₅O₁₇ Ga/ Hf/ Fe/ Cr/ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ La₃NdO₆ Ga/ Hf/ Fe/ Cr/ La₃NdO₆ La₃NdO₆ La₃NdO₆ La₃NdO₆ LaNd₃O₆ Ga/ Hf/ Fe/ Cr/ LaNd₃O₆ LaNd₃O₆ LaNd₃O₆ LaNd₃O₆ La_(1,5)Nd_(2,5)O₆ Ga/ Hf/ Fe/ Cr/ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(2,5)Nd_(1,5)O₆ Ga/ Hf/ Fe/ Cr/ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(3,2)Nd_(0,8)O₆ Ga/ Hf/ Fe/ Cr/ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,5)Nd_(0,5)O₆ Ga/ Hf/ Fe/ Cr/ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,8)Nd_(0,2)O₆ Ga/ Hf/ Fe/ Cr/ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ Y—La Ga/ Hf/ Fe/ Cr/ Y—La Y—La Y—La Y—La Zr—La Ga/ Hf/ Fe/ Cr/ Zr—La Zr—La Zr—La Zr—La Pr—La Ga/ Hf/ Fe/ Cr/ Pr—La Pr—La Pr—La Pr—La Ce—La Ga/ Hf/ Fe/ Cr/ Ce—La Ce—La Ce—La Ce—La

TABLE 6 NANOWIRES (NW) DOPED WITH SPECIFIC DOPANTS (DOP) Dop NW Ru Zr Ta Rh Li₂O Ru/ Zr/ Ta/ Rh/ Li₂O Li₂O Li₂O Li₂O Na₂O Ru/ Zr/ Ta/ Rh/ Na₂O Na₂O Na₂O Na₂O K₂O Ru/ Zr/ Ta/ Rh/ K₂O K₂O K₂O K₂O Rb₂O Ru/ Zr/ Ta/ Rh/ Rb₂O Rb₂O Rb₂O Rb₂O Cs₂O Ru/ Zr/ Ta/ Rh/ Cs₂O Cs₂O Cs₂O Cs₂O BeO Ru/ Zr/ Ta/ Rh/ BeO BeO BeO BeO MgO Ru/ Zr/ Ta/ Rh/ MgO MgO MgO MgO CaO Ru/ Zr/ Ta/ Rh/ CaO CaO CaO CaO SrO Ru/ Zr/ Ta/ Rh/ SrO SrO SrO SrO BaO Ru/ Zr/ Ta/ Rh/ BaO BaO BaO BaO Sc₂O₃ Ru/ Zr/ Ta/ Rh/ Sc₂O₃ Sc₂O₃ Sc₂O₃ Sc₂O₃ Y₂O₃ Ru/ Zr/ Ta/ Rh/ Y₂O₃ Y₂O₃ Y₂O₃ Y₂O₃ La₂O₃ Ru/ Zr/ Ta/ Rh/ La₂O₃ La₂O₃ La₂O₃ La₂O₃ CeO₂ Ru/ Zr/ Ta/ Rh/ CeO₂ CeO₂ CeO₂ CeO₂ Ce₂O₃ Ru/ Zr/ Ta/ Rh/ Ce₂O₃ Ce₂O₃ Ce₂O₃ Ce₂O₃ Pr₂O₃ Ru/ Zr/ Ta/ Rh/ Pr₂O₃ Pr₂O₃ Pr₂O₃ Pr₂O₃ Nd₂O₃ Ru/ Zr/ Ta/ Rh/ Nd₂O₃ Nd₂O₃ Nd₂O₃ Nd₂O₃ Sm₂O₃ Ru/ Zr/ Ta/ Rh/ Sm₂O₃ Sm₂O₃ Sm₂O₃ Sm₂O₃ Eu₂O₃ Ru/ Zr/ Ta/ Rh/ Eu₂O₃ Eu₂O₃ Eu₂O₃ Eu₂O₃ Gd₂O₃ Ru/ Zr/ Ta/ Rh/ Gd₂O₃ Gd₂O₃ Gd₂O₃ Gd₂O₃ Tb₂O₃ Ru/ Zr/ Ta/ Rh/ Tb₂O₃ Tb₂O₃ Tb₂O₃ Tb₂O₃ TbO₂ Ru/ Zr/ Ta/ Rh/ TbO₂ TbO₂ TbO₂ TbO₂ Tb₆O₁₁ Ru/ Zr/ Ta/ Rh/ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Dy₂O₃ Ru/ Zr/ Ta/ Rh/ Dy₂O₃ Dy₂O₃ Dy₂O₃ Dy₂O₃ Ho₂O₃ Ru/ Zr/ Ta/ Rh/ Ho₂O₃ Ho₂O₃ Ho₂O₃ Ho₂O₃ Er₂O₃ Ru/ Zr/ Ta/ Rh/ Er₂O₃ Er₂O₃ Er₂O₃ Er₂O₃ Tm₂O₃ Ru/ Zr/ Ta/ Rh/ Tm₂O₃ Tm₂O₃ Tm₂O₃ Tm₂O₃ Yb₂O₃ Ru/ Zr/ Ta/ Rh/ Yb₂O₃ Yb₂O₃ Yb₂O₃ Yb₂O₃ Lu₂O₃ Ru/ Zr/ Ta/ Rh/ Lu₂O₃ Lu₂O₃ Lu₂O₃ Lu₂O₃ Ac₂O₃ Ru/ Zr/ Ta/ Rh/ Ac₂O₃ Ac₂O₃ Ac₂O₃ Ac₂O₃ Th₂O₃ Ru/ Zr/ Ta/ Rh/ Th₂O₃ Th₂O₃ Th₂O₃ Th₂O₃ ThO₂ Ru/ Zr/ Ta/ Rh/ ThO₂ ThO₂ ThO₂ ThO₂ Pa₂O₃ Ru/ Zr/ Ta/ Rh/ Pa₂O₃ Pa₂O₃ Pa₂O₃ Pa₂O₃ PaO₂ Ru/ Zr/ Ta/ Rh/ PaO₂ PaO₂ PaO₂ PaO₂ TiO₂ Ru/ Zr/ Ta/ Rh/ TiO₂ TiO₂ TiO₂ TiO₂ TiO Ru/ Zr/ Ta/ Rh/ TiO TiO TiO TiO Ti₂O₃ Ru/ Zr/ Ta/ Rh/ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₃O Ru/ Zr/ Ta/ Rh/ Ti₃O Ti₃O Ti₃O Ti₃O Ti₂O Ru/ Zr/ Ta/ Rh/ Ti₂O Ti₂O Ti₂O Ti₂O Ti₃O₅ Ru/ Zr/ Ta/ Rh/ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₄O₇ Ru/ Zr/ Ta/ Rh/ Ti₄O₇ Ti₄O₇ Ti₄O₇ Ti₄O₇ ZrO₂ Ru/ Zr/ Ta/ Rh/ ZrO₂ ZrO₂ ZrO₂ ZrO₂ HfO₂ Ru/ Zr/ Ta/ Rh/ HfO₂ HfO₂ HfO₂ HfO₂ VO Ru/ Zr/ Ta/ Rh/ VO VO VO VO V₂O₃ Ru/ Zr/ Ta/ Rh/ V₂O₃ V₂O₃ V₂O₃ V₂O₃ VO₂ Ru/ Zr/ Ta/ Rh/ VO₂ VO₂ VO₂ VO₂ V₂O₅ Ru/ Zr/ Ta/ Rh/ V₂O₅ V₂O₅ V₂O₅ V₂O₅ V₃O₇ Ru/ Zr/ Ta/ Rh/ V₃O₇ V₃O₇ V₃O₇ V₃O₇ V₄O₉ Ru/ Zr/ Ta/ Rh/ V₄O₉ V₄O₉ V₄O₉ V₄O₉ V₆O₁₃ Ru/ Zr/ Ta/ Rh/ V₆O₁₃ V₆O₁₃ V₆O₁₃ V₆O₁₃ NbO Ru/ Zr/ Ta/ Rh/ NbO NbO NbO NbO NbO₂ Ru/ Zr/ Ta/ Rh/ NbO₂ NbO₂ NbO₂ NbO₂ Nb₂O₅ Ru/ Zr/ Ta/ Rh/ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₈O₁₉ Ru/ Zr/ Ta/ Rh/ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ Ru/ Zr/ Ta/ Rh/ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₂O₂₉ Ru/ Zr/ Ta/ Rh/ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₄₇O₁₁₆ Ru/ Zr/ Ta/ Rh/ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Ta₂O₅ Ru/ Zr/ Ta/ Rh/ Ta₂O₅ Ta₂O₅ Ta₂O₅ Ta₂O₅ CrO Ru/ Zr/ Ta/ Rh/ CrO CrO CrO CrO Cr₂O₃ Ru/ Zr/ Ta/ Rh/ Cr₂O₃ Cr₂O₃ Cr₂O₃ Cr₂O₃ CrO₂ Ru/ Zr/ Ta/ Rh/ CrO₂ CrO₂ CrO₂ CrO₂ CrO₃ Ru/ Zr/ Ta/ Rh/ CrO₃ CrO₃ CrO₃ CrO₃ Cr₈O₂₁ Ru/ Zr/ Ta/ Rh/ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ MoO₂ Ru/ Zr/ Ta/ Rh/ MoO₂ MoO₂ MoO₂ MoO₂ MoO₃ Ru/ Zr/ Ta/ Rh/ MoO₃ MoO₃ MoO₃ MoO₃ W₂O₃ Ru/ Zr/ Ta/ Rh/ W₂O₃ W₂O₃ W₂O₃ W₂O₃ WoO₂ Ru/ Zr/ Ta/ Rh/ WoO₂ WoO₂ WoO₂ WoO₂ WoO₃ Ru/ Zr/ Ta/ Rh/ WoO₃ WoO₃ WoO₃ WoO₃ MnO Ru/ Zr/ Ta/ Rh/ MnO MnO MnO MnO Mn/Mg/O Ru/ Zr/ Ta/ Rh/ Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn₃O₄ Ru/ Zr/ Ta/ Rh/ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₂O₃ Ru/ Zr/ Ta/ Rh/ Mn₂O₃ Mn₂O₃ Mn₂O₃ Mn₂O₃ MnO₂ Ru/ Zr/ Ta/ Rh/ MnO₂ MnO₂ MnO₂ MnO₂ Mn₂O₇ Ru/ Zr/ Ta/ Rh/ Mn₂O₇ Mn₂O₇ Mn₂O₇ Mn₂O₇ ReO₂ Ru/ Zr/ Ta/ Rh/ ReO₂ ReO₂ ReO₂ ReO₂ ReO₃ Ru/ Zr/ Ta/ Rh/ ReO₃ ReO₃ ReO₃ ReO₃ Re₂O₇ Ru/ Zr/ Ta/ Rh/ Re₂O₇ Re₂O₇ Re₂O₇ Re₂O₇ Mg₃Mn₃—B₂O₁₀ Ru/ Zr/ Ta/ Rh/ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂ Ru/ Zr/ Ta/ Rh/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ NaWO₄ Ru/ Zr/ Ta/ Rh/ NaWO₄ NaWO₄ NaWO₄ NaWO₄ Mg₆MnO₈ Ru/ Zr/ Ta/ Rh/ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mn₂O₄ Ru/ Zr/ Ta/ Rh/ Mn₂O₄ Mn₂O₄ Mn₂O₄ Mn₂O₄ (Li,Mg)₆—MnO₈ Ru/ Zr/ Ta/ Rh/ (Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ Na₄P₂O₇ Ru/ Zr/ Ta/ Rh/ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Mo₂O₈ Ru/ Zr/ Ta/ Rh/ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mn₃O₄/WO₄ Ru/ Zr/ Ta/ Rh/ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Na₂WO₄ Ru/ Zr/ Ta/ Rh/ Na₂WO₄ Na₂WO₄ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ Ru/ Zr/ Ta/ Rh/ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ NaMnO₄−/ Ru/ Zr/ Ta/ Rh/ MgO NaMnO₄−/ NaMnO₄−/ NaMnO₄−/ NaMnO₄−/ MgO MgO MgO MgO Na₁₀Mn—W₅O₁₇ Ru/ Zr/ Ta/ Rh/ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ La₃NdO₆ Ru/ Zr/ Ta/ Rh/ La₃NdO₆ La₃NdO₆ La₃NdO₆ La₃NdO₆ LaNd₃O₆ Ru/ Zr/ Ta/ Rh/ LaNd₃O₆ LaNd₃O₆ LaNd₃O₆ LaNd₃O₆ La_(1,5)Nd_(2,5)O₆ Ru/ Zr/ Ta/ Rh/ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(2,5)Nd_(1,5)O₆ Ru/ Zr/ Ta/ Rh/ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(3,2)Nd_(0,8)O₆ Ru/ Zr/ Ta/ Rh/ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,5)Nd_(0,5)O₆ Ru/ Zr/ Ta/ Rh/ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,8)Nd_(0,2)O₆ Ru/ Zr/ Ta/ Rh/ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ Y—La Ru/ Zr/ Ta/ Rh/ Y—La Y—La Y—La Y—La Zr—La Ru/ Zr/ Ta/ Rh/ Zr—La Zr—La Zr—La Zr—La Pr—La Ru/ Zr/ Ta/ Rh/ Pr—La Pr—La Pr—La Pr—La Ce—La Ru/ Zr/ Ta/ Rh/ Ce—La Ce—La Ce—La Ce—La Dop NW Au Mo Ni Li₂O Au/ Mo/ Ni/ Li₂O Li₂O Li₂O Na₂O Au/ Mo/ Ni/ Na₂O Na₂O Na₂O K₂O Au/ Mo/ Ni/ K₂O K₂O K₂O Rb₂O Au/ Mo/ Ni/ Rb₂O Rb₂O Rb₂O Cs₂O Au/ Mo/ Ni/ Cs₂O Cs₂O Cs₂O BeO Au/ Mo/ Ni/ BeO BeO BeO MgO Au/ Mo/ Ni/ MgO MgO MgO CaO Au/ Mo/ Ni/ CaO CaO CaO SrO Au/ Mo/ Ni/ SrO SrO SrO BaO Au/ Mo/ Ni/ BaO BaO BaO Sc₂O₃ Au/ Mo/ Ni/ Sc₂O₃ Sc₂O₃ Sc₂O₃ Y₂O₃ Au/ Mo/ Ni/ Y₂O₃ Y₂O₃ Y₂O₃ La₂O₃ Au/ Mo/ Ni/ La₂O₃ La₂O₃ La₂O₃ CeO₂ Au/ Mo/ Ni/ CeO₂ CeO₂ CeO₂ Ce₂O₃ Au/ Mo/ Ni/ Ce₂O₃ Ce₂O₃ Ce₂O₃ Pr₂O₃ Au/ Mo/ Ni/ Pr₂O₃ Pr₂O₃ Pr₂O₃ Nd₂O₃ Au/ Mo/ Ni/ Nd₂O₃ Nd₂O₃ Nd₂O₃ Sm₂O₃ Au/ Mo/ Ni/ Sm₂O₃ Sm₂O₃ Sm₂O₃ Eu₂O₃ Au/ Mo/ Ni/ Eu₂O₃ Eu₂O₃ Eu₂O₃ Gd₂O₃ Au/ Mo/ Ni/ Gd₂O₃ Gd₂O₃ Gd₂O₃ Tb₂O₃ Au/ Mo/ Ni/ Tb₂O₃ Tb₂O₃ Tb₂O₃ TbO₂ Au/ Mo/ Ni/ TbO₂ TbO₂ TbO₂ Tb₆O₁₁ Au/ Mo/ Ni/ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Dy₂O₃ Au/ Mo/ Ni/ Dy₂O₃ Dy₂O₃ Dy₂O₃ Ho₂O₃ Au/ Mo/ Ni/ Ho₂O₃ Ho₂O₃ Ho₂O₃ Er₂O₃ Au/ Mo/ Ni/ Er₂O₃ Er₂O₃ Er₂O₃ Tm₂O₃ Au/ Mo/ Ni/ Tm₂O₃ Tm₂O₃ Tm₂O₃ Yb₂O₃ Au/ Mo/ Ni/ Yb₂O₃ Yb₂O₃ Yb₂O₃ Lu₂O₃ Au/ Mo/ Ni/ Lu₂O₃ Lu₂O₃ Lu₂O₃ Ac₂O₃ Au/ Mo/ Ni/ Ac₂O₃ Ac₂O₃ Ac₂O₃ Th₂O₃ Au/ Mo/ Ni/ Th₂O₃ Th₂O₃ Th₂O₃ ThO₂ Au/ Mo/ Ni/ ThO₂ ThO₂ ThO₂ Pa₂O₃ Au/ Mo/ Ni/ Pa₂O₃ Pa₂O₃ Pa₂O₃ PaO₂ Au/ Mo/ Ni/ PaO₂ PaO₂ PaO₂ TiO₂ Au/ Mo/ Ni/ TiO₂ TiO₂ TiO₂ TiO Au/ Mo/ Ni/ TiO TiO TiO Ti₂O₃ Au/ Mo/ Ni/ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₃O Au/ Mo/ Ni/ Ti₃O Ti₃O Ti₃O Ti₂O Au/ Mo/ Ni/ Ti₂O Ti₂O Ti₂O Ti₃O₅ Au/ Mo/ Ni/ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₄O₇ Au/ Mo/ Ni/ Ti₄O₇ Ti₄O₇ Ti₄O₇ ZrO₂ Au/ Mo/ Ni/ ZrO₂ ZrO₂ ZrO₂ HfO₂ Au/ Mo/ Ni/ HfO₂ HfO₂ HfO₂ VO Au/ Mo/ Ni/ VO VO VO V₂O₃ Au/ Mo/ Ni/ V₂O₃ V₂O₃ V₂O₃ VO₂ Au/ Mo/ Ni/ VO₂ VO₂ VO₂ V₂O₅ Au/ Mo/ Ni/ V₂O₅ V₂O₅ V₂O₅ V₃O₇ Au/ Mo/ Ni/ V₃O₇ V₃O₇ V₃O₇ V₄O₉ Au/ Mo/ Ni/ V₄O₉ V₄O₉ V₄O₉ V₆O₁₃ Au/ Mo/ Ni/ V₆O₁₃ V₆O₁₃ V₆O₁₃ NbO Au/ Mo/ Ni/ NbO NbO NbO NbO₂ Au/ Mo/ Ni/ NbO₂ NbO₂ NbO₂ Nb₂O₅ Au/ Mo/ Ni/ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₈O₁₉ Au/ Mo/ Ni/ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ Au/ Mo/ Ni/ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₂O₂₉ Au/ Mo/ Ni/ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₄₇O₁₁₆ Au/ Mo/ Ni/ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Ta₂O₅ Au/ Mo/ Ni/ Ta₂O₅ Ta₂O₅ Ta₂O₅ CrO Au/ Mo/ Ni/ CrO CrO CrO Cr₂O₃ Au/ Mo/ Ni/ Cr₂O₃ Cr₂O₃ Cr₂O₃ CrO₂ Au/ Mo/ Ni/ CrO₂ CrO₂ CrO₂ CrO₃ Au/ Mo/ Ni/ CrO₃ CrO₃ CrO₃ Cr₈O₂₁ Au/ Mo/ Ni/ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ MoO₂ Au/ Mo/ Ni/ MoO₂ MoO₂ MoO₂ MoO₃ Au/ Mo/ Ni/ MoO₃ MoO₃ MoO₃ W₂O₃ Au/ Mo/ Ni/ W₂O₃ W₂O₃ W₂O₃ WoO₂ Au/ Mo/ Ni/ WoO₂ WoO₂ WoO₂ WoO₃ Au/ Mo/ Ni/ WoO₃ WoO₃ WoO₃ MnO Au/ Mo/ Ni/ MnO MnO MnO Mn/Mg/O Au/ Mo/ Ni/ Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn₃O₄ Au/ Mo/ Ni/ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₂O₃ Au/ Mo/ Ni/ Mn₂O₃ Mn₂O₃ Mn₂O₃ MnO₂ Au/ Mo/ Ni/ MnO₂ MnO₂ MnO₂ Mn₂O₇ Au/ Mo/ Ni/ Mn₂O₇ Mn₂O₇ Mn₂O₇ ReO₂ Au/ Mo/ Ni/ ReO₂ ReO₂ ReO₂ ReO₃ Au/ Mo/ Ni/ ReO₃ ReO₃ ReO₃ Re₂O₇ Au/ Mo/ Ni/ Re₂O₇ Re₂O₇ Re₂O₇ Mg₃Mn₃—B₂O₁₀ Au/ Mo/ Ni/ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂ Au/ Mo/ Ni/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ NaWO₄ Au/ Mo/ Ni/ NaWO₄ NaWO₄ NaWO₄ Mg₆MnO₈ Au/ Mo/ Ni/ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mn₂O₄ Au/ Mo/ Ni/ Mn₂O₄ Mn₂O₄ Mn₂O₄ (Li,Mg)₆—MnO₈ Au/ Mo/ Ni/ (Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ Na₄P₂O₇ Au/ Mo/ Ni/ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Mo₂O₈ Au/ Mo/ Ni/ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mn₃O₄/WO₄ Au/ Mo/ Ni/ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Na₂WO₄ Au/ Mo/ Ni/ Na₂WO₄ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ Au/ Mo/ Ni/ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ NaMnO₄−/ Au/ Mo/ Ni/ MgO NaMnO₄−/ NaMnO₄−/ NaMnO₄−/ MgO MgO MgO Na₁₀Mn—W₅O₁₇ Au/ Mo/ Ni/ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ La₃NdO₆ Au/ Mo/ Ni/ La₃NdO₆ La₃NdO₆ La₃NdO₆ LaNd₃O₆ Au/ Mo/ Ni/ LaNd₃O₆ LaNd₃O₆ LaNd₃O₆ La_(1,5)Nd_(2,5)O₆ Au/ Mo/ Ni/ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(2,5)Nd_(1,5)O₆ Au/ Mo/ Ni/ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(3,2)Nd_(0,8)O₆ Au/ Mo/ Ni/ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,5)Nd_(0,5)O₆ Au/ Mo/ Ni/ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,8)Nd_(0,2)O₆ Au/ Mo/ Ni/ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ Y—La Au/ Mo/ Ni/ Y—La Y—La Y—La Zr—La Au/ Mo/ Ni/ Zr—La Zr—La Zr—La Pr—La Au/ Mo/ Ni/ Pr—La Pr—La Pr—La Ce—La Au/ Mo/ Ni/ Ce—La Ce—La Ce—La

TABLE 7 NANOWIRES (NW) DOPED WITH SPECIFIC DOPANTS (DOP) Dop NW Co Sb W V Li₂O Co/ Sb/ W/ V/ Li₂O Li₂O Li₂O Li₂O Na₂O Co/ Sb/ W/ V/ Na₂O Na₂O Na₂O Na₂O K₂O Co/ Sb/ W/ V/ K₂O K₂O K₂O K₂O Rb₂O Co/ Sb/ W/ V/ Rb₂O Rb₂O Rb₂O Rb₂O Cs₂O Co/ Sb/ W/ V/ Cs₂O Cs₂O Cs₂O Cs₂O BeO Co/ Sb/ W/ V/ BeO BeO BeO BeO MgO Co/ Sb/ W/ V/ MgO MgO MgO MgO CaO Co/ Sb/ W/ V/ CaO CaO CaO CaO SrO Co/ Sb/ W/ V/ SrO SrO SrO SrO BaO Co/ Sb/ W/ V/ BaO BaO BaO BaO Sc₂O₃ Co/ Sb/ W/ V/ Sc₂O₃ Sc₂O₃ Sc₂O₃ Sc₂O₃ Y₂O₃ Co/ Sb/ W/ V/ Y₂O₃ Y₂O₃ Y₂O₃ Y₂O₃ La₂O₃ Co/ Sb/ W/ V/ La₂O₃ La₂O₃ La₂O₃ La₂O₃ CeO₂ Co/ Sb/ W/ V/ CeO₂ CeO₂ CeO₂ CeO₂ Ce₂O₃ Co/ Sb/ W/ V/ Ce₂O₃ Ce₂O₃ Ce₂O₃ Ce₂O₃ Pr₂O₃ Co/ Sb/ W/ V/ Pr₂O₃ Pr₂O₃ Pr₂O₃ Pr₂O₃ Nd₂O₃ Co/ Sb/ W/ V/ Nd₂O₃ Nd₂O₃ Nd₂O₃ Nd₂O₃ Sm₂O₃ Co/ Sb/ W/ V/ Sm₂O₃ Sm₂O₃ Sm₂O₃ Sm₂O₃ Eu₂O₃ Co/ Sb/ W/ V/ Eu₂O₃ Eu₂O₃ Eu₂O₃ Eu₂O₃ Gd₂O₃ Co/ Sb/ W/ V/ Gd₂O₃ Gd₂O₃ Gd₂O₃ Gd₂O₃ Tb₂O₃ Co/ Sb/ W/ V/ Tb₂O₃ Tb₂O₃ Tb₂O₃ Tb₂O₃ TbO₂ Co/ Sb/ W/ V/ TbO₂ TbO₂ TbO₂ TbO₂ Tb₆O₁₁ Co/ Sb/ W/ V/ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Dy₂O₃ Co/ Sb/ W/ V/ Dy₂O₃ Dy₂O₃ Dy₂O₃ Dy₂O₃ Ho₂O₃ Co/ Sb/ W/ V/ Ho₂O₃ Ho₂O₃ Ho₂O₃ Ho₂O₃ Er₂O₃ Co/ Sb/ W/ V/ Er₂O₃ Er₂O₃ Er₂O₃ Er₂O₃ Tm₂O₃ Co/ Sb/ W/ V/ Tm₂O₃ Tm₂O₃ Tm₂O₃ Tm₂O₃ Yb₂O₃ Co/ Sb/ W/ V/ Yb₂O₃ Yb₂O₃ Yb₂O₃ Yb₂O₃ Lu₂O₃ Co/ Sb/ W/ V/ Lu₂O₃ Lu₂O₃ Lu₂O₃ Lu₂O₃ Ac₂O₃ Co/ Sb/ W/ V/ Ac₂O₃ Ac₂O₃ Ac₂O₃ Ac₂O₃ Th₂O₃ Co/ Sb/ W/ V/ Th₂O₃ Th₂O₃ Th₂O₃ Th₂O₃ ThO₂ Co/ Sb/ W/ V/ ThO₂ ThO₂ ThO₂ ThO₂ Pa₂O₃ Co/ Sb/ W/ V/ Pa₂O₃ Pa₂O₃ Pa₂O₃ Pa₂O₃ PaO₂ Co/ Sb/ W/ V/ PaO₂ PaO₂ PaO₂ PaO₂ TiO₂ Co/ Sb/ W/ V/ TiO₂ TiO₂ TiO₂ TiO₂ TiO Co/ Sb/ W/ V/ TiO TiO TiO TiO Ti₂O₃ Co/ Sb/ W/ V/ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₃O Co/ Sb/ W/ V/ Ti₃O Ti₃O Ti₃O Ti₃O Ti₂O Co/ Sb/ W/ V/ Ti₂O Ti₂O Ti₂O Ti₂O Ti₃O₅ Co/ Sb/ W/ V/ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₄O₇ Co/ Sb/ W/ V/ Ti₄O₇ Ti₄O₇ Ti₄O₇ Ti₄O₇ ZrO₂ Co/ Sb/ W/ V/ ZrO₂ ZrO₂ ZrO₂ ZrO₂ HfO₂ Co/ Sb/ W/ V/ HfO₂ HfO₂ HfO₂ HfO₂ VO Co/ Sb/ W/ V/ VO VO VO VO V₂O₃ Co/ Sb/ W/ V/ V₂O₃ V₂O₃ V₂O₃ V₂O₃ VO₂ Co/ Sb/ W/ V/ VO₂ VO₂ VO₂ VO₂ V₂O₅ Co/ Sb/ W/ V/ V₂O₅ V₂O₅ V₂O₅ V₂O₅ V₃O₇ Co/ Sb/ W/ V/ V₃O₇ V₃O₇ V₃O₇ V₃O₇ V₄O₉ Co/ Sb/ W/ V/ V₄O₉ V₄O₉ V₄O₉ V₄O₉ V₆O₁₃ Co/ Sb/ W/ V/ V₆O₁₃ V₆O₁₃ V₆O₁₃ V₆O₁₃ NbO Co/ Sb/ W/ V/ NbO NbO NbO NbO NbO₂ Co/ Sb/ W/ V/ NbO₂ NbO₂ NbO₂ NbO₂ Nb₂O₅ Co/ Sb/ W/ V/ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₈O₁₉ Co/ Sb/ W/ V/ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ Co/ Sb/ W/ V/ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₂O₂₉ Co/ Sb/ W/ V/ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₄₇O₁₁₆ Co/ Sb/ W/ V/ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Ta₂O₅ Co/ Sb/ W/ V/ Ta₂O₅ Ta₂O₅ Ta₂O₅ Ta₂O₅ CrO Co/ Sb/ W/ V/ CrO CrO CrO CrO Cr₂O₃ Co/ Sb/ W/ V/ Cr₂O₃ Cr₂O₃ Cr₂O₃ Cr₂O₃ CrO₂ Co/ Sb/ W/ V/ CrO₂ CrO₂ CrO₂ CrO₂ CrO₃ Co/ Sb/ W/ V/ CrO₃ CrO₃ CrO₃ CrO₃ Cr₈O₂₁ Co/ Sb/ W/ V/ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ MoO₂ Co/ Sb/ W/ V/ MoO₂ MoO₂ MoO₂ MoO₂ MoO₃ Co/ Sb/ W/ V/ MoO₃ MoO₃ MoO₃ MoO₃ W₂O₃ Co/ Sb/ W/ V/ W₂O₃ W₂O₃ W₂O₃ W₂O₃ WoO₂ Co/ Sb/ W/ V/ WoO₂ WoO₂ WoO₂ WoO₂ WoO₃ Co/ Sb/ W/ V/ WoO₃ WoO₃ WoO₃ WoO₃ MnO Co/ Sb/ W/ V/ MnO MnO MnO MnO Mn/Mg/O Co/ Sb/ W/ V/ Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn₃O₄ Co/ Sb/ W/ V/ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₂O₃ Co/ Sb/ W/ V/ Mn₂O₃ Mn₂O₃ Mn₂O₃ Mn₂O₃ MnO₂ Co/ Sb/ W/ V/ MnO₂ MnO₂ MnO₂ MnO₂ Mn₂O₇ Co/ Sb/ W/ V/ Mn₂O₇ Mn₂O₇ Mn₂O₇ Mn₂O₇ ReO₂ Co/ Sb/ W/ V/ ReO₂ ReO₂ ReO₂ ReO₂ ReO₃ Co/ Sb/ W/ V/ ReO₃ ReO₃ ReO₃ ReO₃ Re₂O₇ Co/ Sb/ W/ V/ Re₂O₇ Re₂O₇ Re₂O₇ Re₂O₇ Mg₃Mn₃—B₂O₁₀ Co/ Sb/ W/ V/ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂ Co/ Sb/ W/ V/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ NaWO₄ Co/ Sb/ W/ V/ NaWO₄ NaWO₄ NaWO₄ NaWO₄ Mg₆MnO₈ Co/ Sb/ W/ V/ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mn₂O₄ Co/ Sb/ W/ V/ Mn₂O₄ Mn₂O₄ Mn₂O₄ Mn₂O₄ (Li,Mg)₆—MnO₈ Co/ Sb/ W/ V/ (Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ Na₄P₂O₇ Co/ Sb/ W/ V/ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Mo₂O₈ Co/ Sb/ W/ V/ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mn₃O₄/WO₄ Co/ Sb/ W/ V/ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Na₂WO₄ Co/ Sb/ W/ V/ Na₂WO₄ Na₂WO₄ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ Co/ Sb/ W/ V/ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ NaMnO₄−/ Co/ Sb/ W/ V/ MgO NaMnO₄−/ NaMnO₄−/ NaMnO₄−/ NaMnO₄−/ MgO MgO MgO MgO Na₁₀Mn—W₅O₁₇ Co/ Sb/ W/ V/ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ La₃NdO₆ Co/ Sb/ W/ V/ La₃NdO₆ La₃NdO₆ La₃NdO₆ La₃NdO₆ LaNd₃O₆ Co/ Sb/ W/ V/ LaNd₃O₆ LaNd₃O₆ LaNd₃O₆ LaNd₃O₆ La_(1,5)Nd_(2,5)O₆ Co/ Sb/ W/ V/ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(2,5)Nd_(1,5)O₆ Co/ Sb/ W/ V/ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(3,2)Nd_(0,8)O₆ Co/ Sb/ W/ V/ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,5)Nd_(0,5)O₆ Co/ Sb/ W/ V/ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,8)Nd_(0,2)O₆ Co/ Sb/ W/ V/ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ Y—La Co/ Sb/ W/ V/ Y—La Y—La Y—La Y—La Zr—La Co/ Sb/ W/ V/ Zr—La Zr—La Zr—La Zr—La Pr—La Co/ Sb/ W/ V/ Pr—La Pr—La Pr—La Pr—La Ce—La Co/ Sb/ W/ V/ Ce—La Ce—La Ce—La Ce—La Dop NW Ag Te Pd Ir Li₂O Ag/ Te/ Pd/ Ir/ Li₂O Li₂O Li₂O Li₂O Na₂O Ag/ Te/ Pd/ Ir/ Na₂O Na₂O Na₂O Na₂O K₂O Ag/ Te/ Pd/ Ir/ K₂O K₂O K₂O K₂O Rb₂O Ag/ Te/ Pd/ Ir/ Rb₂O Rb₂O Rb₂O Rb₂O Cs₂O Ag/ Te/ Pd/ Ir/ Cs₂O Cs₂O Cs₂O Cs₂O BeO Ag/ Te/ Pd/ Ir/ BeO BeO BeO BeO MgO Ag/ Te/ Pd/ Ir/ MgO MgO MgO MgO CaO Ag/ Te/ Pd/ Ir/ CaO CaO CaO CaO SrO Ag/ Te/ Pd/ Ir/ SrO SrO SrO SrO BaO Ag/ Te/ Pd/ Ir/ BaO BaO BaO BaO Sc₂O₃ Ag/ Te/ Pd/ Ir/ Sc₂O₃ Sc₂O₃ Sc₂O₃ Sc₂O₃ Y₂O₃ Ag/ Te/ Pd/ Ir/ Y₂O₃ Y₂O₃ Y₂O₃ Y₂O₃ La₂O₃ Ag/ Te/ Pd/ Ir/ La₂O₃ La₂O₃ La₂O₃ La₂O₃ CeO₂ Ag/ Te/ Pd/ Ir/ CeO₂ CeO₂ CeO₂ CeO₂ Ce₂O₃ Ag/ Te/ Pd/ Ir/ Ce₂O₃ Ce₂O₃ Ce₂O₃ Ce₂O₃ Pr₂O₃ Ag/ Te/ Pd/ Ir/ Pr₂O₃ Pr₂O₃ Pr₂O₃ Pr₂O₃ Nd₂O₃ Ag/ Te/ Pd/ Ir/ Nd₂O₃ Nd₂O₃ Nd₂O₃ Nd₂O₃ Sm₂O₃ Ag/ Te/ Pd/ Ir/ Sm₂O₃ Sm₂O₃ Sm₂O₃ Sm₂O₃ Eu₂O₃ Ag/ Te/ Pd/ Ir/ Eu₂O₃ Eu₂O₃ Eu₂O₃ Eu₂O₃ Gd₂O₃ Ag/ Te/ Pd/ Ir/ Gd₂O₃ Gd₂O₃ Gd₂O₃ Gd₂O₃ Tb₂O₃ Ag/ Te/ Pd/ Ir/ Tb₂O₃ Tb₂O₃ Tb₂O₃ Tb₂O₃ TbO₂ Ag/ Te/ Pd/ Ir/ TbO₂ TbO₂ TbO₂ TbO₂ Tb₆O₁₁ Ag/ Te/ Pd/ Ir/ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Dy₂O₃ Ag/ Te/ Pd/ Ir/ Dy₂O₃ Dy₂O₃ Dy₂O₃ Dy₂O₃ Ho₂O₃ Ag/ Te/ Pd/ Ir/ Ho₂O₃ Ho₂O₃ Ho₂O₃ Ho₂O₃ Er₂O₃ Ag/ Te/ Pd/ Ir/ Er₂O₃ Er₂O₃ Er₂O₃ Er₂O₃ Tm₂O₃ Ag/ Te/ Pd/ Ir/ Tm₂O₃ Tm₂O₃ Tm₂O₃ Tm₂O₃ Yb₂O₃ Ag/ Te/ Pd/ Ir/ Yb₂O₃ Yb₂O₃ Yb₂O₃ Yb₂O₃ Lu₂O₃ Ag/ Te/ Pd/ Ir/ Lu₂O₃ Lu₂O₃ Lu₂O₃ Lu₂O₃ Ac₂O₃ Ag/ Te/ Pd/ Ir/ Ac₂O₃ Ac₂O₃ Ac₂O₃ Ac₂O₃ Th₂O₃ Ag/ Te/ Pd/ Ir/ Th₂O₃ Th₂O₃ Th₂O₃ Th₂O₃ ThO₂ Ag/ Te/ Pd/ Ir/ ThO₂ ThO₂ ThO₂ ThO₂ Pa₂O₃ Ag/ Te/ Pd/ Ir/ Pa₂O₃ Pa₂O₃ Pa₂O₃ Pa₂O₃ PaO₂ Ag/ Te/ Pd/ Ir/ PaO₂ PaO₂ PaO₂ PaO₂ TiO₂ Ag/ Te/ Pd/ Ir/ TiO₂ TiO₂ TiO₂ TiO₂ TiO Ag/ Te/ Pd/ Ir/ TiO TiO TiO TiO Ti₂O₃ Ag/ Te/ Pd/ Ir/ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₃O Ag/ Te/ Pd/ Ir/ Ti₃O Ti₃O Ti₃O Ti₃O Ti₂O Ag/ Te/ Pd/ Ir/ Ti₂O Ti₂O Ti₂O Ti₂O Ti₃O₅ Ag/ Te/ Pd/ Ir/ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₄O₇ Ag/ Te/ Pd/ Ir/ Ti₄O₇ Ti₄O₇ Ti₄O₇ Ti₄O₇ ZrO₂ Ag/ Te/ Pd/ Ir/ ZrO₂ ZrO₂ ZrO₂ ZrO₂ HfO₂ Ag/ Te/ Pd/ Ir/ HfO₂ HfO₂ HfO₂ HfO₂ VO Ag/ Te/ Pd/ Ir/ VO VO VO VO V₂O₃ Ag/ Te/ Pd/ Ir/ V₂O₃ V₂O₃ V₂O₃ V₂O₃ VO₂ Ag/ Te/ Pd/ Ir/ VO₂ VO₂ VO₂ VO₂ V₂O₅ Ag/ Te/ Pd/ Ir/ V₂O₅ V₂O₅ V₂O₅ V₂O₅ V₃O₇ Ag/ Te/ Pd/ Ir/ V₃O₇ V₃O₇ V₃O₇ V₃O₇ V₄O₉ Ag/ Te/ Pd/ Ir/ V₄O₉ V₄O₉ V₄O₉ V₄O₉ V₆O₁₃ Ag/ Te/ Pd/ Ir/ V₆O₁₃ V₆O₁₃ V₆O₁₃ V₆O₁₃ NbO Ag/ Te/ Pd/ Ir/ NbO NbO NbO NbO NbO₂ Ag/ Te/ Pd/ Ir/ NbO₂ NbO₂ NbO₂ NbO₂ Nb₂O₅ Ag/ Te/ Pd/ Ir/ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₈O₁₉ Ag/ Te/ Pd/ Ir/ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ Ag/ Te/ Pd/ Ir/ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₂O₂₉ Ag/ Te/ Pd/ Ir/ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₄₇O₁₁₆ Ag/ Te/ Pd/ Ir/ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Ta₂O₅ Ag/ Te/ Pd/ Ir/ Ta₂O₅ Ta₂O₅ Ta₂O₅ Ta₂O₅ CrO Ag/ Te/ Pd/ Ir/ CrO CrO CrO CrO Cr₂O₃ Ag/ Te/ Pd/ Ir/ Cr₂O₃ Cr₂O₃ Cr₂O₃ Cr₂O₃ CrO₂ Ag/ Te/ Pd/ Ir/ CrO₂ CrO₂ CrO₂ CrO₂ CrO₃ Ag/ Te/ Pd/ Ir/ CrO₃ CrO₃ CrO₃ CrO₃ Cr₈O₂₁ Ag/ Te/ Pd/ Ir/ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ MoO₂ Ag/ Te/ Pd/ Ir/ MoO₂ MoO₂ MoO₂ MoO₂ MoO₃ Ag/ Te/ Pd/ Ir/ MoO₃ MoO₃ MoO₃ MoO₃ W₂O₃ Ag/ Te/ Pd/ Ir/ W₂O₃ W₂O₃ W₂O₃ W₂O₃ WoO₂ Ag/ Te/ Pd/ Ir/ WoO₂ WoO₂ WoO₂ WoO₂ WoO₃ Ag/ Te/ Pd/ Ir/ WoO₃ WoO₃ WoO₃ WoO₃ MnO Ag/ Te/ Pd/ Ir/ MnO MnO MnO MnO Mn/Mg/O Ag/ Te/ Pd/ Ir/ Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn₃O₄ Ag/ Te/ Pd/ Ir/ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₂O₃ Ag/ Te/ Pd/ Ir/ Mn₂O₃ Mn₂O₃ Mn₂O₃ Mn₂O₃ MnO₂ Ag/ Te/ Pd/ Ir/ MnO₂ MnO₂ MnO₂ MnO₂ Mn₂O₇ Ag/ Te/ Pd/ Ir/ Mn₂O₇ Mn₂O₇ Mn₂O₇ Mn₂O₇ ReO₂ Ag/ Te/ Pd/ Ir/ ReO₂ ReO₂ ReO₂ ReO₂ ReO₃ Ag/ Te/ Pd/ Ir/ ReO₃ ReO₃ ReO₃ ReO₃ Re₂O₇ Ag/ Te/ Pd/ Ir/ Re₂O₇ Re₂O₇ Re₂O₇ Re₂O₇ Mg₃Mn₃—B₂O₁₀ Ag/ Te/ Pd/ Ir/ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂ Ag/ Te/ Pd/ Ir/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ NaWO₄ Ag/ Te/ Pd/ Ir/ NaWO₄ NaWO₄ NaWO₄ NaWO₄ Mg₆MnO₈ Ag/ Te/ Pd/ Ir/ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mn₂O₄ Ag/ Te/ Pd/ Ir/ Mn₂O₄ Mn₂O₄ Mn₂O₄ Mn₂O₄ (Li,Mg)₆—MnO₈ Ag/ Te/ Pd/ Ir/ (Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ Na₄P₂O₇ Ag/ Te/ Pd/ Ir/ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Mo₂O₈ Ag/ Te/ Pd/ Ir/ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mn₃O₄/WO₄ Ag/ Te/ Pd/ Ir/ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Na₂WO₄ Ag/ Te/ Pd/ Ir/ Na₂WO₄ Na₂WO₄ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ Ag/ Te/ Pd/ Ir/ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ NaMnO₄−/ Ag/ Te/ Pd/ Ir/ MgO NaMnO₄−/ NaMnO₄−/ NaMnO₄−/ NaMnO₄−/ MgO MgO MgO MgO Na₁₀Mn—W₅O₁₇ Ag/ Te/ Pd/ Ir/ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ La₃NdO₆ Ag/ Te/ Pd/ Ir/ La₃NdO₆ La₃NdO₆ La₃NdO₆ La₃NdO₆ LaNd₃O₆ Ag/ Te/ Pd/ Ir/ LaNd₃O₆ LaNd₃O₆ LaNd₃O₆ LaNd₃O₆ La_(1,5)Nd_(2,5)O₆ Ag/ Te/ Pd/ Ir/ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(2,5)Nd_(1,5)O₆ Ag/ Te/ Pd/ Ir/ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(3,2)Nd_(0,8)O₆ Ag/ Te/ Pd/ Ir/ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,5)Nd_(0,5)O₆ Ag/ Te/ Pd/ Ir/ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,8)Nd_(0,2)O₆ Ag/ Te/ Pd/ Ir/ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ Y—La Ag/ Te/ Pd/ Ir/ Y—La Y—La Y—La Y—La Zr—La Ag/ Te/ Pd/ Ir/ Zr—La Zr—La Zr—La Zr—La Pr—La Ag/ Te/ Pd/ Ir/ Pr—La Pr—La Pr—La Pr—La Ce—La Ag/ Te/ Pd/ Ir/ Ce—La Ce—La Ce—La Ce—La

TABLE 8 NANOWIRES (NW) DOPED WITH SPECIFIC DOPANTS (DOP) Dop NW Mn Ti Li₂O Mn/ Ti/ Li₂O Li₂O Na₂O Mn/ Ti/ Na₂O Na₂O K₂O Mn/ Ti/ K₂O K₂O Rb₂O Mn/ Ti/ Rb₂O Rb₂O Cs₂O Mn/ Ti/ Cs₂O Cs₂O BeO Mn/ Ti/ BeO BeO MgO Mn/ Ti/ MgO MgO CaO Mn/ Ti/ CaO CaO SrO Mn/ Ti/ SrO SrO BaO Mn/ Ti/ BaO BaO Sc₂O₃ Mn/ Ti/ Sc₂O₃ Sc₂O₃ Y₂O₃ Mn/ Ti/ Y₂O₃ Y₂O₃ La₂O₃ Mn/ Ti/ La₂O₃ La₂O₃ CeO₂ Mn/ Ti/ CeO₂ CeO₂ Ce₂O₃ Mn/ Ti/ Ce₂O₃ Ce₂O₃ Pr₂O₃ Mn/ Ti/ Pr₂O₃ Pr₂O₃ Nd₂O₃ Mn/ Ti/ Nd₂O₃ Nd₂O₃ Sm₂O₃ Mn/ Ti/ Sm₂O₃ Sm₂O₃ Eu₂O₃ Mn/ Ti/ Eu₂O₃ Eu₂O₃ Gd₂O₃ Mn/ Ti/ Gd₂O₃ Gd₂O₃ Tb₂O₃ Mn/ Ti/ Tb₂O₃ Tb₂O₃ TbO₂ Mn/ Ti/ TbO₂ TbO₂ Tb₆O₁₁ Mn/ Ti/ Tb₆O₁₁ Tb₆O₁₁ Dy₂O₃ Mn/ Ti/ Dy₂O₃ Dy₂O₃ Ho₂O₃ Mn/ Ti/ Ho₂O₃ Ho₂O₃ Er₂O₃ Mn/ Ti/ Er₂O₃ Er₂O₃ Tm₂O₃ Mn/ Ti/ Tm₂O₃ Tm₂O₃ Yb₂O₃ Mn/ Ti/ Yb₂O₃ Yb₂O₃ Lu₂O₃ Mn/ Ti/ Lu₂O₃ Lu₂O₃ Ac₂O₃ Mn/ Ti/ Ac₂O₃ Ac₂O₃ Th₂O₃ Mn/ Ti/ Th₂O₃ Th₂O₃ ThO₂ Mn/ Ti/ ThO₂ ThO₂ Pa₂O₃ Mn/ Ti/ Pa₂O₃ Pa₂O₃ PaO₂ Mn/ Ti/ PaO₂ PaO₂ TiO₂ Mn/ Ti/ TiO₂ TiO₂ TiO Mn/ Ti/ TiO TiO Ti₂O₃ Mn/ Ti/ Ti₂O₃ Ti₂O₃ Ti₃O Mn/ Ti/ Ti₃O Ti₃O Ti₂O Mn/ Ti/ Ti₂O Ti₂O Ti₃O₅ Mn/ Ti/ Ti₃O₅ Ti₃O₅ Ti₄O₇ Mn/ Ti/ Ti₄O₇ Ti₄O₇ ZrO₂ Mn/ Ti/ ZrO₂ ZrO₂ HfO₂ Mn/ Ti/ HfO₂ HfO₂ VO Mn/ Ti/ VO VO V₂O₃ Mn/ Ti/ V₂O₃ V₂O₃ VO₂ Mn/ Ti/ VO₂ VO₂ V₂O₅ Mn/ Ti/ V₂O₅ V₂O₅ V₃O₇ Mn/ Ti/ V₃O₇ V₃O₇ V₄O₉ Mn/ Ti/ V₄O₉ V₄O₉ V₆O₁₃ Mn/ Ti/ V₆O₁₃ V₆O₁₃ NbO Mn/ Ti/ NbO NbO NbO₂ Mn/ Ti/ NbO₂ NbO₂ Nb₂O₅ Mn/ Ti/ Nb₂O₅ Nb₂O₅ Nb₈O₁₉ Mn/ Ti/ Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ Mn/ Ti/ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₂O₂₉ Mn/ Ti/ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₄₇O₁₁₆ Mn/ Ti/ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Ta₂O₅ Mn/ Ti/ Ta₂O₅ Ta₂O₅ CrO Mn/ Ti/ CrO CrO Cr₂O₃ Mn/ Ti/ Cr₂O₃ Cr₂O₃ CrO₂ Mn/ Ti/ CrO₂ CrO₂ CrO₃ Mn/ Ti/ CrO₃ CrO₃ Cr₈O₂₁ Mn/ Ti/ Cr₈O₂₁ Cr₈O₂₁ MoO₂ Mn/ Ti/ MoO₂ MoO₂ MoO₃ Mn/ Ti/ MoO₃ MoO₃ W₂O₃ Mn/ Ti/ W₂O₃ W₂O₃ WoO₂ Mn/ Ti/ WoO₂ WoO₂ WoO₃ Mn/ Ti/ WoO₃ WoO₃ MnO Mn/ Ti/ MnO MnO Mn/Mg/O Mn/ Ti/ Mn/Mg/O Mn/Mg/O Mn₃O₄ Mn/ Ti/ Mn₃O₄ Mn₃O₄ Mn₂O₃ Mn/ Ti/ Mn₂O₃ Mn₂O₃ MnO₂ Mn/ Ti/ MnO₂ MnO₂ Mn₂O₇ Mn/ Ti/ Mn₂O₇ Mn₂O₇ ReO₂ Mn/ Ti/ ReO₂ ReO₂ ReO₃ Mn/ Ti/ ReO₃ ReO₃ Re₂O₇ Mn/ Ti/ Re₂O₇ Re₂O₇ Mg₃Mn₃—B₂O₁₀ Mn/ Ti/ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂ Mn/ Ti/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ NaWO₄ Mn/ Ti/ NaWO₄ NaWO₄ Mg₆MnO₈ Mn/ Ti/ Mg₆MnO₈ Mg₆MnO₈ Mn₂O₄ Mn/ Ti/ Mn₂O₄ Mn₂O₄ (Li,Mg)₆—MnO₈ Mn/ Mn/ (Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ Na₄P₂O₇ Mn/ Ti/ Na₄P₂O₇ Na₄P₂O₇ Mo₂O₈ Mn/ Ti/ Mo₂O₈ Mo₂O₈ Mn₃O₄/WO₄ Mn/ Ti/ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Na₂WO₄ Mn/ Ti/ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ Mn/ Ti/ Zr₂Mo₂O₈ Zr₂Mo₂O₈ NaMnO₄−/ Mn/ Ti/ MgO NaMnO₄−/ NaMnO₄−/ MgO MgO Na₁₀Mn—W₅O₁₇ Mn/ Ti/ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ La₃NdO₆ Mn/ Ti/ La₃NdO₆ La₃NdO₆ LaNd₃O₆ Mn/ Ti/ LaNd₃O₆ LaNd₃O₆ La_(1,5)Nd_(2,5)O₆ Mn/ Ti/ La_(1,5)Nd_(2,5)O₆ La_(1,5)Nd_(2,5)O₆ La_(2,5)Nd_(1,5)O₆ Mn/ Ti/ La_(2,5)Nd_(1,5)O₆ La_(2,5)Nd_(1,5)O₆ La_(3,2)Nd_(0,8)O₆ Mn/ Ti/ La_(3,2)Nd_(0,8)O₆ La_(3,2)Nd_(0,8)O₆ La_(3,5)Nd_(0,5)O₆ Mn/ Ti/ La_(3,5)Nd_(0,5)O₆ La_(3,5)Nd_(0,5)O₆ La_(3,8)Nd_(0,2)O₆ Mn/ Ti/ La_(3,8)Nd_(0,2)O₆ La_(3,8)Nd_(0,2)O₆ Y—La Mn/ Ti/ Y—La Y—La Zr—La Mn/ Ti/ Zr—La Zr—La Pr—La Mn/ Ti/ Pr—La Pr—La Ce—La Mn/ Ti/ Ce—La Ce—La

TABLE 9 NANOWIRES (NW) DOPED WITH SPECIFIC DOPANTS (DOP) NW Dop La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Eu/Na Eu/Na/ Eu/Na/ Eu/Na/ Eu/Na/ Eu/Na/ Eu/Na/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/Na Sr/Na/ Sr/Na/ Sr/Na/ Sr/Na/ Sr/Na/ Sr/Na/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Na/Zr/Eu/Ca Na/Zr/Eu/Ca/ Na/Zr/Eu/Ca/ Na/Zr/Eu/Ca/ Na/Zr/Eu/Ca/ Na/Zr/Eu/Ca/ Na/Zr/Eu/Ca/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Mg/Na Mg/Na/ Mg/Na/ Mg/Na/ Mg/Na/ Mg/Na/ Mg/Na/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/Sm/Ho/Tm Sr/Sm/Ho/Tm/ Sr/Sm/Ho/Tm/ Sr/Sm/Ho/Tm/ Sr/Sm/Ho/Tm/ Sr/Sm/Ho/Tm/ Sr/Sm/Ho/Tm/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/W Sr/W/ Sr/W/ Sr/W/ Sr/W/ Sr/W/ Sr/W/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/Zr Sr/Zr/ Sr/Zr/ Sr/Zr/ Sr/Zr/ Sr/Zr/ Sr/Zr/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ Rb/Sr/ Mg/La/K Mg/La/K/ Mg/La/K/ Mg/La/K/ Mg/La/K/ Mg/La/K/ Mg/La/K/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Na/K/Mg/Tm Na/K/Mg/Tm/ Na/K/Mg/Tm/ Na/K/Mg/Tm/ Na/K/Mg/Tm/ Na/K/Mg/Tm/ Na/K/Mg/Tm/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Na/Dy/K Na/Dy/K/ Na/Dy/K/ Na/Dy/K/ Na/Dy/K/ Na/Dy/K/ Na/Dy/K/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Na/La/Dy Na/La/Dy/ Na/La/Dy/ Na/La/Dy/ Na/La/Dy/ Na/La/Dy/ Na/La/Dy/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Na/La/Eu Na/La/Eu/ Na/La/Eu/ Na/La/Eu/ Na/La/Eu/ Na/La/Eu/ Na/La/Eu/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Na/La/Eu/In Na/La/Eu/In/ Na/La/Eu/In/ Na/La/Eu/In/ Na/La/Eu/In/ Na/La/Eu/In/ Na/La/Eu/In/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/Ce Sr/Ce/ Sr/Ce/ Sr/Ce/ Sr/Ce/ Sr/Ce/ Sr/Ce/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ Rb/Sr/ Na/La/K Na/La/K/ Na/La/K/ Na/La/K/ Na/La/K/ Na/La/K/ Na/La/K/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Na/La/Li/Cs Na/La/Li/Cs/ Na/La/Li/Cs/ Na/La/Li/Cs/ Na/La/Li/Cs/ Na/La/Li/Cs/ Na/La/Li/Cs/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ K/La K/La/ K/La/ K/La/ K/La/ K/La/ K/La/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ K/La/S K/La/S/ K/La/S/ K/La/S/ K/La/S/ K/La/S/ K/La/S/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ K/Na K/Na/ K/Na/ K/Na/ K/Na/ K/Na/ K/Na/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Li/Cs Li/Cs/ Li/Cs/ Li/Cs/ Li/Cs/ Li/Cs/ Li/Cs/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Li/Cs/La Li/Cs/La/ Li/Cs/La/ Li/Cs/La/ Li/Cs/La/ Li/Cs/La/ Li/Cs/La/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Li/Cs/La/Tm Li/Cs/La/Tm/ Li/Cs/La/Tm/ Li/Cs/La/Tm/ Li/Cs/La/Tm/ Li/Cs/La/Tm/ Li/Cs/La/Tm/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/Tb Sr/Tb/ Sr/Tb/ Sr/Tb/ Sr/Tb/ Sr/Tb/ Sr/Tb/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ Rb/Sr/ Li/Cs/Sr/Tm Li/Cs/Sr/Tm/ Li/Cs/Sr/Tm/ Li/Cs/Sr/Tm/ Li/Cs/Sr/Tm/ Li/Cs/Sr/Tm/ Li/Cs/Sr/Tm/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Li/Sr/Cs Li/Sr/Cs/ Li/Sr/Cs/ Li/Sr/Cs/ Li/Sr/Cs/ Li/Sr/Cs/ Li/Sr/Cs/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Li/Sr/Zn/K Li/Sr/Zn/K/ Li/Sr/Zn/K/ Li/Sr/Zn/K/ Li/Sr/Zn/K/ Li/Sr/Zn/K/ Li/Sr/Zn/K/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Li/Ga/Cs Li/Ga/Cs/ Li/Ga/Cs/ Li/Ga/Cs/ Li/Ga/Cs/ Li/Ga/Cs/ Li/Ga/Cs/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Li/K/Sr/La Li/K/Sr/La/ Li/K/Sr/La/ Li/K/Sr/La/ Li/K/Sr/La/ Li/K/Sr/La/ Li/K/Sr/La/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Li/Na Li/Na/ Li/Na/ Li/Na/ Li/Na/ Li/Na/ Li/Na/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Li/Na/Rb/Ga Li/Na/Rb/Ga/ Li/Na/Rb/Ga/ Li/Na/Rb/Ga/ Li/Na/Rb/Ga/ Li/Na/Rb/Ga/ Li/Na/Rb/Ga/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Li/Na/Sr Li/Na/Sr/ Li/Na/Sr/ Li/Na/Sr/ Li/Na/Sr/ Li/Na/Sr/ Li/Na/Sr/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Li/Na/Sr/La Li/Na/Sr/La/ Li/Na/Sr/La/ Li/Na/Sr/La/ Li/Na/Sr/La/ Li/Na/Sr/La/ Li/Na/Sr/La/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Li/Sm/Cs Li/Sm/Cs/ Li/Sm/Cs/ Li/Sm/Cs/ Li/Sm/Cs/ Li/Sm/Cs/ Li/Sm/Cs/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Ba/Sm/Yb/S Ba/Sm/Yb/S/ Ba/Sm/Yb/S/ Ba/Sm/Yb/S/ Ba/Sm/Yb/S/ Ba/Sm/Yb/S/ Ba/Sm/Yb/S/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/Ce/K Sr/Ce/K/ Sr/Ce/K/ Sr/Ce/K/ Sr/Ce/K/ Sr/Ce/K/ Sr/Ce/K/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ Rb/Sr/ Ba/Tm/K/La Ba/Tm/K/La/ Ba/Tm/K/La/ Ba/Tm/K/La/ Ba/Tm/K/La/ Ba/Tm/K/La/ Ba/Tm/K/La/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Ba/Tm/Zn/K Ba/Tm/Zn/K/ Ba/Tm/Zn/K/ Ba/Tm/Zn/K/ Ba/Tm/Zn/K/ Ba/Tm/Zn/K/ Ba/Tm/Zn/K/ La2O3 Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Cs/K/La Cs/K/La/ Cs/K/La/ Cs/K/La/ Cs/K/La/ Cs/K/La/ Cs/K/La/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Cs/La/Tm/Na Cs/La/Tm/Na/ Cs/La/Tm/Na/ Cs/La/Tm/Na/ Cs/La/Tm/Na/ Cs/La/Tm/Na/ Cs/La/Tm/Na/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Cs/Li/K/La Cs/Li/K/La/ Cs/Li/K/La/ Cs/Li/K/La/ Cs/Li/K/La/ Cs/Li/K/La/ Cs/Li/K/La/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sm/Li/Sr/Cs Sm/Li/Sr/Cs/ Sm/Li/Sr/Cs/ Sm/Li/Sr/Cs/ Sm/Li/Sr/Cs/ Sm/Li/Sr/Cs/ Sm/Li/Sr/Cs/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/Cs/La Sr/Cs/La/ Sr/Cs/La/ Sr/Cs/La/ Sr/Cs/La/ Sr/Cs/La/ Sr/Cs/La/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/Tm/Li/Cs Sr/Tm/Li/Cs/ Sr/Tm/Li/Cs/ Sr/Tm/Li/Cs/ Sr/Tm/Li/Cs/ Sr/Tm/Li/Cs/ Sr/Tm/Li/Cs/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Zn/K Zn/K/ Zn/K/ Zn/K/ Zn/K/ Zn/K/ Zn/K/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Zr/Cs/K/La Zr/Cs/K/La/ Zr/Cs/K/La/ Zr/Cs/K/La/ Zr/Cs/K/La/ Zr/Cs/K/La/ Zr/Cs/K/La/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Rb/Ca/In/Ni Rb/Ca/In/Ni/ Rb/Ca/In/Ni/ Rb/Ca/In/Ni/ Rb/Ca/In/Ni/ Rb/Ca/In/Ni/ Rb/Ca/In/Ni/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/Ho/Tm Sr/Ho/Tm/ Sr/Ho/Tm/ Sr/Ho/Tm/ Sr/Ho/Tm/ Sr/Ho/Tm/ Sr/Ho/Tm/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ La/Nd/S La/Nd/S/ La/Nd/S/ La/Nd/S/ La/Nd/S/ La/Nd/S/ La/Nd/S/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Li/Rb/Ca Li/Rb/Ca/ Li/Rb/Ca/ Li/Rb/Ca/ Li/Rb/Ca/ Li/Rb/Ca/ Li/Rb/Ca/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Li/K Li/K/ Li/K/ Li/K/ Li/K/ Li/K/ Li/K/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Tm/Lu/Ta/P Tm/Lu/Ta/P/ Tm/Lu/Ta/P/ Tm/Lu/Ta/P/ Tm/Lu/Ta/P/ Tm/Lu/Ta/P/ Tm/Lu/Ta/P/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Rb/Ca/Dy/P Rb/Ca/Dy/P/ Rb/Ca/Dy/P/ Rb/Ca/Dy/P/ Rb/Ca/Dy/P/ Rb/Ca/Dy/P/ Rb/Ca/Dy/P/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Mg/La/Yb/Zn Mg/La/Yb/Zn/ Mg/La/Yb/Zn/ Mg/La/Yb/Zn/ Mg/La/Yb/Zn/ Mg/La/Yb/Zn/ Mg/La/Yb/Zn/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/Zr/K Sr/Zr/K/ Sr/Zr/K/ Sr/Zr/K/ Sr/Zr/K/ Sr/Zr/K/ Sr/Zr/K/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ Rb/Sr/ Rb/Sr/Lu Rb/Sr/Lu/ Rb/Sr/Lu/ Rb/Sr/Lu/ Rb/Sr/Lu/ Rb/Sr/Lu/ Rb/Sr/Lu/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Na/Sr/Lu/Nb Na/Sr/Lu/Nb/ Na/Sr/Lu/Nb/ Na/Sr/Lu/Nb/ Na/Sr/Lu/Nb/ Na/Sr/Lu/Nb/ Na/Sr/Lu/Nb/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Na/Eu/Hf Na/Eu/Hf/ Na/Eu/Hf/ Na/Eu/Hf/ Na/Eu/Hf/ Na/Eu/Hf/ Na/Eu/Hf/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Dy/Rb/Gd Dy/Rb/Gd/ Dy/Rb/Gd/ Dy/Rb/Gd/ Dy/Rb/Gd/ Dy/Rb/Gd/ Dy/Rb/Gd/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Na/Pt/Bi Na/Pt/Bi/ Na/Pt/Bi/ Na/Pt/Bi/ Na/Pt/Bi/ Na/Pt/Bi/ Na/Pt/Bi/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Rb/Hf Rb/Hf/ Rb/Hf/ Rb/Hf/ Rb/Hf/ Rb/Hf/ Rb/Hf/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Ca/Cs Ca/Cs/ Ca/Cs/ Ca/Cs/ Ca/Cs/ Ca/Cs/ Ca/Cs/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Ca/Mg/Na Ca/Mg/Na/ Ca/Mg/Na/ Ca/Mg/Na/ Ca/Mg/Na/ Ca/Mg/Na/ Ca/Mg/Na/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Hf/Bi Hf/Bi/ Hf/Bi/ Hf/Bi/ Hf/Bi/ Hf/Bi/ Hf/Bi/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/Sn Sr/Sn/ Sr/Sn/ Sr/Sn/ Sr/Sn/ Sr/Sn/ Sr/Sn/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/Pr/K Sr/Pr/K/ Sr/Pr/K/ Sr/Pr/K/ Sr/Pr/K/ Sr/Pr/K/ Sr/Pr/K/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ Rb/Sr/ Sr/W Sr/W/ Sr/W/ Sr/W/ Sr/W/ Sr/W/ Sr/W/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/Nb Sr/Nb/ Sr/Nb/ Sr/Nb/ Sr/Nb/ Sr/Nb/ Sr/Nb/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Zr/W Zr/W/ Zr/W/ Zr/W/ Zr/W/ Zr/W/ Zr/W/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Y/W Y/W/ Y/W/ Y/W/ Y/W/ Y/W/ Y/W/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Na/W Na/W/ Na/W/ Na/W/ Na/W/ Na/W/ Na/W/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Bi/W Bi/W/ Bi/W/ Bi/W/ Bi/W/ Bi/W/ Bi/W/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Bi/Cs Bi/Cs/ Bi/Cs/ Bi/Cs/ Bi/Cs/ Bi/Cs/ Bi/Cs/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Bi/Ca Bi/Ca/ Bi/Ca/ Bi/Ca/ Bi/Ca/ Bi/Ca/ Bi/Ca/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Bi/Sn Bi/Sn/ Bi/Sn/ Bi/Sn/ Bi/Sn/ Bi/Sn/ Bi/Sn/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Bi/Sb Bi/Sb/ Bi/Sb/ Bi/Sb/ Bi/Sb/ Bi/Sb/ Bi/Sb/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Ge/Hf Ge/Hf/ Ge/Hf/ Ge/Hf/ Ge/Hf/ Ge/Hf/ Ge/Hf/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Hf/Sm Hf/Sm/ Hf/Sm/ Hf/Sm/ Hf/Sm/ Hf/Sm/ Hf/Sm/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sb/Ag Sb/Ag/ Sb/Ag/ Sb/Ag/ Sb/Ag/ Sb/Ag/ Sb/Ag/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sb/Bi Sb/Bi/ Sb/Bi/ Sb/Bi/ Sb/Bi/ Sb/Bi/ Sb/Bi/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sb/Au Sb/Au/ Sb/Au/ Sb/Au/ Sb/Au/ Sb/Au/ Sb/Au/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sb/Sm Sb/Sm/ Sb/Sm/ Sb/Sm/ Sb/Sm/ Sb/Sm/ Sb/Sm/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/Tb/K Sr/Tb/K/ Sr/Tb/K/ Sr/Tb/K/ Sr/Tb/K/ Sr/Tb/K/ Sr/Tb/K/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ Rb/Sr/ Sb/Sr Sb/Sr/ Sb/Sr/ Sb/Sr/ Sb/Sr/ Sb/Sr/ Sb/Sr/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sb/W Sb/W/ Sb/W/ Sb/W/ Sb/W/ Sb/W/ Sb/W/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sb/Hf Sb/Hf/ Sb/Hf/ Sb/Hf/ Sb/Hf/ Sb/Hf/ Sb/Hf/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sb/Yb Sb/Yb/ Sb/Yb/ Sb/Yb/ Sb/Yb/ Sb/Yb/ Sb/Yb/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sb/Sn Sb/Sn/ Sb/Sn/ Sb/Sn/ Sb/Sn/ Sb/Sn/ Sb/Sn/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Yb/Au Yb/Au/ Yb/Au/ Yb/Au/ Yb/Au/ Yb/Au/ Yb/Au/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Yb/Ta Yb/Ta/ Yb/Ta/ Yb/Ta/ Yb/Ta/ Yb/Ta/ Yb/Ta/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Yb/W Yb/W/ Yb/W/ Yb/W/ Yb/W/ Yb/W/ Yb/W/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Yb/Sr Yb/Sr/ Yb/Sr/ Yb/Sr/ Yb/Sr/ Yb/Sr/ Yb/Sr/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Yb/Pb Yb/Pb/ Yb/Pb/ Yb/Pb/ Yb/Pb/ Yb/Pb/ Yb/Pb/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Yb/W Yb/W/ Yb/W/ Yb/W/ Yb/W/ Yb/W/ Yb/W/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Yb/Ag Yb/Ag/ Yb/Ag/ Yb/Ag/ Yb/Ag/ Yb/Ag/ Yb/Ag/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Au/Sr Au/Sr/ Au/Sr/ Au/Sr/ Au/Sr/ Au/Sr/ Au/Sr/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/Hf/K Sr/Hf/K/ Sr/Hf/K/ Sr/Hf/K/ Sr/Hf/K/ Sr/Hf/K/ Sr/Hf/K/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ Rb/Sr/ W/Ge W/Ge/ W/Ge/ W/Ge/ W/Ge/ W/Ge/ W/Ge/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Ta/Sr Ta/Sr/ Ta/Sr/ Ta/Sr/ Ta/Sr/ Ta/Sr/ Ta/Sr/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Ta/Hf Ta/Hf/ Ta/Hf/ Ta/Hf/ Ta/Hf/ Ta/Hf/ Ta/Hf/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ W/Au W/Au/ W/Au/ W/Au/ W/Au/ W/Au/ W/Au/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Ca/W Ca/W/ Ca/W/ Ca/W/ Ca/W/ Ca/W/ Ca/W/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Au/Re Au/Re/ Au/Re/ Au/Re/ Au/Re/ Au/Re/ Au/Re/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sm/Li Sm/Li/ Sm/Li/ Sm/Li/ Sm/Li/ Sm/Li/ Sm/Li/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ La/K La/K/ La/K/ La/K/ La/K/ La/K/ La/K/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Zn/Cs Zn/Cs/ Zn/Cs/ Zn/Cs/ Zn/Cs/ Zn/Cs/ Zn/Cs/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Na/K/Mg Na/K/Mg/ Na/K/Mg/ Na/K/Mg/ Na/K/Mg/ Na/K/Mg/ Na/K/Mg/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Zr/Cs Zr/Cs/ Zr/Cs/ Zr/Cs/ Zr/Cs/ Zr/Cs/ Zr/Cs/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Ca/Ce Ca/Ce/ Ca/Ce/ Ca/Ce/ Ca/Ce/ Ca/Ce/ Ca/Ce/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Na/Li/Cs Na/Li/Cs/ Na/Li/Cs/ Na/Li/Cs/ Na/Li/Cs/ Na/Li/Cs/ Na/Li/Cs/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Li/Sr Li/Sr/ Li/Sr/ Li/Sr/ Li/Sr/ Li/Sr/ Li/Sr/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ La/Dy/K La/Dy/K/ La/Dy/K/ La/Dy/K/ La/Dy/K/ La/Dy/K/ La/Dy/K/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/Pr Sr/Pr/ Sr/Pr/ Sr/Pr/ Sr/Pr/ Sr/Pr/ Sr/Pr/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ Rb/Sr/ Dy/K Dy/K/ Dy/K/ Dy/K/ Dy/K/ Dy/K/ Dy/K/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ La/Mg La/Mg/ La/Mg/ La/Mg/ La/Mg/ La/Mg/ La/Mg/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Na/Nd/In/K Na/Nd/In/K/ Na/Nd/In/K/ Na/Nd/In/K/ Na/Nd/In/K/ Na/Nd/In/K/ Na/Nd/In/K/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ In/Sr In/Sr/ In/Sr/ In/Sr/ In/Sr/ In/Sr/ In/Sr/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/Cs Sr/Cs/ Sr/Cs/ Sr/Cs/ Sr/Cs/ Sr/Cs/ Sr/Cs/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Rb/Ga/Tm/Cs Rb/Ga/Tm/Cs/ Rb/Ga/Tm/Cs/ Rb/Ga/Tm/Cs/ Rb/Ga/Tm/Cs/ Rb/Ga/Tm/Cs/ Rb/Ga/Tm/Cs/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Ga/Cs Ga/Cs/ Ga/Cs/ Ga/Cs/ Ga/Cs/ Ga/Cs/ Ga/Cs/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ K/La/Zr/Ag K/La/Zr/Ag/ K/La/Zr/Ag/ K/La/Zr/Ag/ K/La/Zr/Ag/ K/La/Zr/Ag/ K/La/Zr/Ag/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Lu/Fe Lu/Fe/ Lu/Fe/ Lu/Fe/ Lu/Fe/ Lu/Fe/ Lu/Fe/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/Tm Sr/Tm/ Sr/Tm/ Sr/Tm/ Sr/Tm/ Sr/Tm/ Sr/Tm/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ La/Dy La/Dy/ La/Dy/ La/Dy/ La/Dy/ La/Dy/ La/Dy/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sm/Li/Sr Sm/Li/Sr/ Sm/Li/Sr/ Sm/Li/Sr/ Sm/Li/Sr/ Sm/Li/Sr/ Sm/Li/Sr/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Mg/K Mg/K/ Mg/K/ Mg/K/ Mg/K/ Mg/K/ Mg/K/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Li/Rb/Ga Li/Rb/Ga/ Li/Rb/Ga/ Li/Rb/Ga/ Li/Rb/Ga/ Li/Rb/Ga/ Li/Rb/Ga/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Li/Cs/Tm Li/Cs/Tm/ Li/Cs/Tm/ Li/Cs/Tm/ Li/Cs/Tm/ Li/Cs/Tm/ Li/Cs/Tm/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Zr/K Zr/K/ Zr/K/ Zr/K/ Zr/K/ Zr/K/ Zr/K/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/Hf/Rb Sr/Hf/Rb/ Sr/Hf/Rb/ Sr/Hf/Rb/ Sr/Hf/Rb/ Sr/Hf/Rb/ Sr/Hf/Rb/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ Rb/Sr/ Li/Cs Li/Cs/ Li/Cs/ Li/Cs/ Li/Cs/ Li/Cs/ Li/Cs/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Li/K/La Li/K/La/ Li/K/La/ Li/K/La/ Li/K/La/ Li/K/La/ Li/K/La/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Ce/Zr/La Ce/Zr/La/ Ce/Zr/La/ Ce/Zr/La/ Ce/Zr/La/ Ce/Zr/La/ Ce/Zr/La/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Ca/Al/La Ca/Al/La/ Ca/Al/La/ Ca/Al/La/ Ca/Al/La/ Ca/Al/La/ Ca/Al/La/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/Zn/La Sr/Zn/La/ Sr/Zn/La/ Sr/Zn/La/ Sr/Zn/La/ Sr/Zn/La/ Sr/Zn/La/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/Cs/Zn Sr/Cs/Zn/ Sr/Cs/Zn/ Sr/Cs/Zn/ Sr/Cs/Zn/ Sr/Cs/Zn/ Sr/Cs/Zn/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sm/Cs Sm/Cs/ Sm/Cs/ Sm/Cs/ Sm/Cs/ Sm/Cs/ Sm/Cs/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ In/K In/K/ In/K/ In/K/ In/K/ In/K/ In/K/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Ho/Cs/Li/La Ho/Cs/Li/La/ Ho/Cs/Li/La/ Ho/Cs/Li/La/ Ho/Cs/Li/La/ Ho/Cs/Li/La/ Ho/Cs/Li/La/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Cs/La/Na Cs/La/Na/ Cs/La/Na/ Cs/La/Na/ Cs/La/Na/ Cs/La/Na/ Cs/La/Na/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ La/S/Sr La/S/Sr/ La/S/Sr/ La/S/Sr/ La/S/Sr/ La/S/Sr/ La/S/Sr/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ K/La/Zr/Ag K/La/Zr/Ag/ K/La/Zr/Ag/ K/La/Zr/Ag/ K/La/Zr/Ag/ K/La/Zr/Ag/ K/La/Zr/Ag/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Lu/Tl Lu/Tl/ Lu/Tl/ Lu/Tl/ Lu/Tl/ Lu/Tl/ Lu/Tl/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Pr/Zn Pr/Zn/ Pr/Zn/ Pr/Zn/ Pr/Zn/ Pr/Zn/ Pr/Zn/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Rb/Sr/La Rb/Sr/La/ Rb/Sr/La/ Rb/Sr/La/ Rb/Sr/La/ Rb/Sr/La/ Rb/Sr/La/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Na/Sr/Eu/Ca Na/Sr/Eu/Ca/ Na/Sr/Eu/Ca/ Na/Sr/Eu/Ca/ Na/Sr/Eu/Ca/ Na/Sr/Eu/Ca/ Na/Sr/Eu/Ca/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/B Sr/B/ Sr/B/ Sr/B/ Sr/B/ Sr/B/ Sr/B/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ Rb/Sr/ K/Cs/Sr/La K/Cs/Sr/La/ K/Cs/Sr/La/ K/Cs/Sr/La/ K/Cs/Sr/La/ K/Cs/Sr/La/ K/Cs/Sr/La/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Na/Sr/Lu Na/Sr/Lu/ Na/Sr/Lu/ Na/Sr/Lu/ Na/Sr/Lu/ Na/Sr/Lu/ Na/Sr/Lu/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/Eu/Dy Sr/Eu/Dy/ Sr/Eu/Dy/ Sr/Eu/Dy/ Sr/Eu/Dy/ Sr/Eu/Dy/ Sr/Eu/Dy/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Lu/Nb Lu/Nb/ Lu/Nb/ Lu/Nb/ Lu/Nb/ Lu/Nb/ Lu/Nb/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ La/Dy/Gd La/Dy/Gd/ La/Dy/Gd/ La/Dy/Gd/ La/Dy/Gd/ La/Dy/Gd/ La/Dy/Gd/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Na/Mg/Tl/P Na/Mg/Tl/P/ Na/Mg/Tl/P/ Na/Mg/Tl/P/ Na/Mg/Tl/P/ Na/Mg/Tl/P/ Na/Mg/Tl/P/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Na/Pt Na/Pt/ Na/Pt/ Na/Pt/ Na/Pt/ Na/Pt/ Na/Pt/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Gd/Li/K Gd/Li/K/ Gd/Li/K/ Gd/Li/K/ Gd/Li/K/ Gd/Li/K/ Gd/Li/K/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Rb/K/Lu Rb/K/Lu/ Rb/K/Lu/ Rb/K/Lu/ Rb/K/Lu/ Rb/K/Lu/ Rb/K/Lu/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/La/Dy/S Sr/La/Dy/S/ Sr/La/Dy/S/ Sr/La/Dy/S/ Sr/La/Dy/S/ Sr/La/Dy/S/ Sr/La/Dy/S/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Na/Ce/Co Na/Ce/Co/ Na/Ce/Co/ Na/Ce/Co/ Na/Ce/Co/ Na/Ce/Co/ Na/Ce/Co/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Na/Ce Na/Ce/ Na/Ce/ Na/Ce/ Na/Ce/ Na/Ce/ Na/Ce/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Na/Ga/Gd/Al Na/Ga/Gd/Al/ Na/Ga/Gd/Al/ Na/Ga/Gd/Al/ Na/Ga/Gd/Al/ Na/Ga/Gd/Al/ Na/Ga/Gd/Al/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Ba/Rh/Ta Ba/Rh/Ta/ Ba/Rh/Ta/ Ba/Rh/Ta/ Ba/Rh/Ta/ Ba/Rh/Ta/ Ba/Rh/Ta/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Ba/Ta Ba/Ta/ Ba/Ta/ Ba/Ta/ Ba/Ta/ Ba/Ta/ Ba/Ta/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Na/Al/Bi Na/Al/Bi/ Na/Al/Bi/ Na/Al/Bi/ Na/Al/Bi/ Na/Al/Bi/ Na/Al/Bi/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Cs/Eu/S Cs/Eu/S/ Cs/Eu/S/ Cs/Eu/S/ Cs/Eu/S/ Cs/Eu/S/ Cs/Eu/S/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sm/Tm/Yb/Fe Sm/Tm/Yb/Fe/ Sm/Tm/Yb/Fe/ Sm/Tm/Yb/Fe/ Sm/Tm/Yb/Fe/ Sm/Tm/Yb/Fe/ Sm/Tm/Yb/Fe/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sm/Tm/Yb Sm/Tm/Yb/ Sm/Tm/Yb/ Sm/Tm/Yb/ Sm/Tm/Yb/ Sm/Tm/Yb/ Sm/Tm/Yb/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Hf/Zr/Ta Hf/Zr/Ta/ Hf/Zr/Ta/ Hf/Zr/Ta/ Hf/Zr/Ta/ Hf/Zr/Ta/ Hf/Zr/Ta/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Rb/Gd/Li/K Rb/Gd/Li/K/ Rb/Gd/Li/K/ Rb/Gd/Li/K/ Rb/Gd/Li/K/ Rb/Gd/Li/K/ Rb/Gd/Li/K/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Gd/Ho/Al/P Gd/Ho/Al/P/ Gd/Ho/Al/P/ Gd/Ho/Al/P/ Gd/Ho/Al/P/ Gd/Ho/Al/P/ Gd/Ho/Al/P/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Na/Ca/Lu Na/Ca/Lu/ Na/Ca/Lu/ Na/Ca/Lu/ Na/Ca/Lu/ Na/Ca/Lu/ Na/Ca/Lu/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Cu/Sn Cu/Sn/ Cu/Sn/ Cu/Sn/ Cu/Sn/ Cu/Sn/ Cu/Sn/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Ag/Au Ag/Au/ Ag/Au/ Ag/Au/ Ag/Au/ Ag/Au/ Ag/Au/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Al/Bi Al/Bi/ Al/Bi/ Al/Bi/ Al/Bi/ Al/Bi/ Al/Bi/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Al/Mo Al/Mo/ Al/Mo/ Al/Mo/ Al/Mo/ Al/Mo/ Al/Mo/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Al/Nb Al/Nb/ Al/Nb/ Al/Nb/ Al/Nb/ Al/Nb/ Al/Nb/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Au/Pt Au/Pt/ Au/Pt/ Au/Pt/ Au/Pt/ Au/Pt/ Au/Pt/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Ga/Bi Ga/Bi/ Ga/Bi/ Ga/Bi/ Ga/Bi/ Ga/Bi/ Ga/Bi/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Mg/W Mg/W/ Mg/W/ Mg/W/ Mg/W/ Mg/W/ Mg/W/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Pb/Au Pb/Au/ Pb/Au/ Pb/Au/ Pb/Au/ Pb/Au/ Pb/Au/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sn/Mg Sn/Mg/ Sn/Mg/ Sn/Mg/ Sn/Mg/ Sn/Mg/ Sn/Mg/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Zn/Bi Zn/Bi/ Zn/Bi/ Zn/Bi/ Zn/Bi/ Zn/Bi/ Zn/Bi/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/Ta Sr/Ta/ Sr/Ta/ Sr/Ta/ Sr/Ta/ Sr/Ta/ Sr/Ta/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Na Na/ Na/ Na/ Na/ Na/ Na/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr Sr/ Sr/ Sr/ Sr/ Sr/ Sr/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Ca Ca/ Ca/ Ca/ Ca/ Ca/ Ca/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Yb Yb/ Yb/ Yb/ Yb/ Yb/ Yb/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Cs Cs/ Cs/ Cs/ Cs/ Cs/ Cs/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sb Sb/ Sb/ Sb/ Sb/ Sb/ Sb/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Gd/Ho Gd/Ho/ Gd/Ho/ Gd/Ho/ Gd/Ho/ Gd/Ho/ Gd/Ho/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Zr/Bi Zr/Bi/ Zr/Bi/ Zr/Bi/ Zr/Bi/ Zr/Bi/ Zr/Bi/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Ho/Sr Ho/Sr/ Ho/Sr/ Ho/Sr/ Ho/Sr/ Ho/Sr/ Ho/Sr/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Gd/Ho/Sr Gd/Ho/Sr/ Gd/Ho/Sr/ Gd/Ho/Sr/ Gd/Ho/Sr/ Gd/Ho/Sr/ Gd/Ho/Sr/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Ca/Sr Ca/Sr/ Ca/Sr/ Ca/Sr/ Ca/Sr/ Ca/Sr/ Ca/Sr/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Ca/Sr/W Ca/Sr/W/ Ca/Sr/W/ Ca/Sr/W/ Ca/Sr/W/ Ca/Sr/W/ Ca/Sr/W/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Na/Zr/Eu/Tm Na/Zr/Eu/Tm/ Na/Zr/Eu/Tm/ Na/Zr/Eu/Tm/ Na/Zr/Eu/Tm/ Na/Zr/Eu/Tm/ Na/Zr/Eu/Tm/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/Ho/ Sr/Ho/Tm/Na/ Sr/Ho/Tm/Na/ Sr/Ho/Tm/Na/ Sr/Ho/Tm/Na/ Sr/Ho/Tm/Na/ Sr/Ho/Tm/Na/ Tm/Na La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/Pb Sr/Pb/ Sr/Pb/ Sr/Pb/ Sr/Pb/ Sr/Pb/ Sr/Pb/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/W/Li Sr/W/Li/ Sr/W/Li/ Sr/W/Li/ Sr/W/Li/ Sr/W/Li/ Sr/W/Li/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Ca/Sr/W Ca/Sr/W/ Ca/Sr/W/ Ca/Sr/W/ Ca/Sr/W/ Ca/Sr/W/ Ca/Sr/W/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/Hf Sr/Hf/ Sr/Hf/ Sr/Hf/ Sr/Hf/ Sr/Hf/ Sr/Hf/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Au/Re Au/Re/ Au/Re/ Au/Re/ Au/Re/ Au/Re/ Au/Re/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/W Sr/W/ Sr/W/ Sr/W/ Sr/W/ Sr/W/ Sr/W/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ La/Nd La/Nd/ La/Nd/ La/Nd/ La/Nd/ La/Nd/ La/Nd/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ La/Sm La/Sm/ La/Sm/ La/Sm/ La/Sm/ La/Sm/ La/Sm/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ La/Ce La/Ce/ La/Ce/ La/Ce/ La/Ce/ La/Ce/ La/Ce/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ La/Sr La/Sr/ La/Sr/ La/Sr/ La/Sr/ La/Sr/ La/Sr/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ La/Nd/Sr La/Nd/Sr/ La/Nd/Sr/ La/Nd/Sr/ La/Nd/Sr/ La/Nd/Sr/ La/Nd/Sr/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ La/Bi/Sr La/Bi/Sr/ La/Bi/Sr/ La/Bi/Sr/ La/Bi/Sr/ La/Bi/Sr/ La/Bi/Sr/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ La/Ce/Nd/Sr La/Ce/Nd/Sr/ La/Ce/Nd/Sr/ La/Ce/Nd/Sr/ La/Ce/Nd/Sr/ La/Ce/Nd/Sr/ La/Ce/Nd/Sr/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ La/Bi/Ce/Nd/Sr La/Bi/Ce/Nd/Sr/ La/Bi/Ce/Nd/Sr/ La/Bi/Ce/Nd/Sr/ La/Bi/Ce/Nd/Sr/ La/Bi/Ce/Nd/Sr/ La/Bi/Ce/Nd/Sr/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Eu/Gd Eu/Gd/ Eu/Gd/ Eu/Gd/ Eu/Gd/ Eu/Gd/ Eu/Gd/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Ca/Na Ca/Na/ Ca/Na/ Ca/Na/ Ca/Na/ Ca/Na/ Ca/Na/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Eu/Sm Eu/Sm/ Eu/Sm/ Eu/Sm/ Eu/Sm/ Eu/Sm/ Eu/Sm/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Eu/Sr Eu/Sr/ Eu/Sr/ Eu/Sr/ Eu/Sr/ Eu/Sr/ Eu/Sr/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Mg/Sr Mg/Sr/ Mg/Sr/ Mg/Sr/ Mg/Sr/ Mg/Sr/ Mg/Sr/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Ce/Mg Ce/Mg/ Ce/Mg/ Ce/Mg/ Ce/Mg/ Ce/Mg/ Ce/Mg/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Gd/Sm Gd/Sm/ Gd/Sm/ Gd/Sm/ Gd/Sm/ Gd/Sm/ Gd/Sm/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Au/Pb Au/Pb/ Au/Pb/ Au/Pb/ Au/Pb/ Au/Pb/ Au/Pb/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Bi/Hf Bi/Hf/ Bi/Hf/ Bi/Hf/ Bi/Hf/ Bi/Hf/ Bi/Hf/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Rb/S Rb/S/ Rb/S/ Rb/S/ Rb/S/ Rb/S/ Rb/S/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Sr/Nd Sr/Nd/ Sr/Nd/ Sr/Nd/ Sr/Nd/ Sr/Nd/ Sr/Nd/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Eu/Y Eu/Y/ Eu/Y/ Eu/Y/ Eu/Y/ Eu/Y/ Eu/Y/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Mg/Nd Mg/Nd/ Mg/Nd/ Mg/Nd/ Mg/Nd/ Mg/Nd/ Mg/Nd/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ La/Mg La/Mg/ La/Mg/ La/Mg/ La/Mg/ La/Mg/ La/Mg/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Mg/Nd/Fe Mg/Nd/Fe/ Mg/Nd/Fe/ Mg/Nd/Fe/ Mg/Nd/Fe/ Mg/Nd/Fe/ Mg/Nd/Fe/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ La₃NdO₆ Rb/Sr Rb/Sr/ Rb/Sr/ Rb/Sr/ Rb/Sr/ Rb/Sr/ Rb/Sr/ La₂O₃ Nd₂O₃ Yb₂O₃ Eu₂O₃ Sm₂O₃ Rb/Sr/

TABLE 10 NANOWIRES (NW) DOPED WITH SPECIFIC DOPANTS (DOP) NW Dop La_(4−X)Nd_(X)O₆* LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Eu/Na Eu/Na/ Eu/Na/ Eu/Na/ Eu/Na/ Eu/Na/ Eu/Na/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/Na Sr/Na/ Sr/Na/ Sr/Na/ Sr/Na/ Sr/Na/ Sr/Na/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Na/Zr/Eu/Ca Na/Zr/Eu/Ca/ Na/Zr/Eu/Ca/ Na/Zr/Eu/Ca/ Na/Zr/Eu/Ca/ Na/Zr/Eu/Ca/ Na/Zr/Eu/Ca/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Mg/Na Mg/Na/ Mg/Na/ Mg/Na/ Mg/Na/ Mg/Na/ Mg/Na/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/Sm/Ho/Tm Sr/Sm/Ho/Tm/ Sr/Sm/Ho/Tm/ Sr/Sm/Ho/Tm/ Sr/Sm/Ho/Tm/ Sr/Sm/Ho/Tm/ Sr/Sm/Ho/Tm/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/W Sr/W/ Sr/W/ Sr/W/ Sr/W/ Sr/W/ Sr/W/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Mg/La/K Mg/La/K/ Mg/La/K/ Mg/La/K/ Mg/La/K/ Mg/La/K/ Mg/La/K/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Na/K/Mg/Tm Na/K/Mg/Tm/ Na/K/Mg/Tm/ Na/K/Mg/Tm/ Na/K/Mg/Tm/ Na/K/Mg/Tm/ Na/K/Mg/Tm/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Na/Dy/K Na/Dy/K/ Na/Dy/K/ Na/Dy/K/ Na/Dy/K/ Na/Dy/K/ Na/Dy/K/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/B Sr/B/ Sr/B/ Sr/B/ Sr/B/ Sr/B/ Sr/B/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Na/La/Dy Na/La/Dy/ Na/La/Dy/ Na/La/Dy/ Na/La/Dy/ Na/La/Dy/ Na/La/Dy/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Na/La/Eu Na/La/Eu/ Na/La/Eu/ Na/La/Eu/ Na/La/Eu/ Na/La/Eu/ Na/La/Eu/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Na/La/Eu/In Na/La/Eu/In/ Na/La/Eu/In/ Na/La/Eu/In/ Na/La/Eu/In/ Na/La/Eu/In/ Na/La/Eu/In/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Na/La/K Na/La/K/ Na/La/K/ Na/La/K/ Na/La/K/ Na/La/K/ Na/La/K/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Na/La/Li/Cs Na/La/Li/Cs/ Na/La/Li/Cs/ Na/La/Li/Cs/ Na/La/Li/Cs/ Na/La/Li/Cs/ Na/La/Li/Cs/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ K/La K/La/ K/La/ K/La/ K/La/ K/La/ K/La/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ K/La/S K/La/S/ K/La/S/ K/La/S/ K/La/S/ K/La/S/ K/La/S/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ K/Na K/Na/ K/Na/ K/Na/ K/Na/ K/Na/ K/Na/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Li/Cs Li/Cs/ Li/Cs/ Li/Cs/ Li/Cs/ Li/Cs/ Li/Cs/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Li/Cs/La Li/Cs/La/ Li/Cs/La/ Li/Cs/La/ Li/Cs/La/ Li/Cs/La/ Li/Cs/La/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Li/Cs/La/Tm Li/Cs/La/Tm/ Li/Cs/La/Tm/ Li/Cs/La/Tm/ Li/Cs/La/Tm/ Li/Cs/La/Tm/ Li/Cs/La/Tm/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Li/Cs/Sr/Tm Li/Cs/Sr/Tm/ Li/Cs/Sr/Tm/ Li/Cs/Sr/Tm/ Li/Cs/Sr/Tm/ Li/Cs/Sr/Tm/ Li/Cs/Sr/Tm/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Li/Sr/Cs Li/Sr/Cs/ Li/Sr/Cs/ Li/Sr/Cs/ Li/Sr/Cs/ Li/Sr/Cs/ Li/Sr/Cs/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Li/Sr/Zn/K Li/Sr/Zn/K/ Li/Sr/Zn/K/ Li/Sr/Zn/K/ Li/Sr/Zn/K/ Li/Sr/Zn/K/ Li/Sr/Zn/K/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/Pr Sr/Pr/ Sr/Pr/ Sr/Pr/ Sr/Pr/ Sr/Pr/ Sr/Pr/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Li/Ga/Cs Li/Ga/Cs/ Li/Ga/Cs/ Li/Ga/Cs/ Li/Ga/Cs/ Li/Ga/Cs/ Li/Ga/Cs/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Li/K/Sr/La Li/K/Sr/La/ Li/K/Sr/La/ Li/K/Sr/La/ Li/K/Sr/La/ Li/K/Sr/La/ Li/K/Sr/La/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Li/Na Li/Na/ Li/Na/ Li/Na/ Li/Na/ Li/Na/ Li/Na/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Li/Na/Rb/Ga Li/Na/Rb/Ga/ Li/Na/Rb/Ga/ Li/Na/Rb/Ga/ Li/Na/Rb/Ga/ Li/Na/Rb/Ga/ Li/Na/Rb/Ga/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Li/Na/Sr Li/Na/Sr/ Li/Na/Sr/ Li/Na/Sr/ Li/Na/Sr/ Li/Na/Sr/ Li/Na/Sr/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Li/Na/Sr/La Li/Na/Sr/La/ Li/Na/Sr/La/ Li/Na/Sr/La/ Li/Na/Sr/La/ Li/Na/Sr/La/ Li/Na/Sr/La/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Li/Sm/Cs Li/Sm/Cs/ Li/Sm/Cs/ Li/Sm/Cs/ Li/Sm/Cs/ Li/Sm/Cs/ Li/Sm/Cs/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Ba/Sm/Yb/S Ba/Sm/Yb/S/ Ba/Sm/Yb/S/ Ba/Sm/Yb/S/ Ba/Sm/Yb/S/ Ba/Sm/Yb/S/ Ba/Sm/Yb/S/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Ba/Tm/K/La Ba/Tm/K/La/ Ba/Tm/K/La/ Ba/Tm/K/La/ Ba/Tm/K/La/ Ba/Tm/K/La/ Ba/Tm/K/La/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Ba/Tm/Zn/K Ba/Tm/Zn/K/ Ba/Tm/Zn/K/ Ba/Tm/Zn/K/ Ba/Tm/Zn/K/ Ba/Tm/Zn/K/ Ba/Tm/Zn/K/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Cs/K/La Cs/K/La/ Cs/K/La/ Cs/K/La/ Cs/K/La/ Cs/K/La/ Cs/K/La/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/Pr/K Sr/Pr/K/ Sr/Pr/K/ Sr/Pr/K/ Sr/Pr/K/ Sr/Pr/K/ Sr/Pr/K/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Cs/La/Tm/Na Cs/La/Tm/Na/ Cs/La/Tm/Na/ Cs/La/Tm/Na/ Cs/La/Tm/Na/ Cs/La/Tm/Na/ Cs/La/Tm/Na/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Cs/Li/K/La Cs/Li/K/La/ Cs/Li/K/La/ Cs/Li/K/La/ Cs/Li/K/La/ Cs/Li/K/La/ Cs/Li/K/La/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sm/Li/Sr/Cs Sm/Li/Sr/Cs/ Sm/Li/Sr/Cs/ Sm/Li/Sr/Cs/ Sm/Li/Sr/Cs/ Sm/Li/Sr/Cs/ Sm/Li/Sr/Cs/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/Cs/La Sr/Cs/La/ Sr/Cs/La/ Sr/Cs/La/ Sr/Cs/La/ Sr/Cs/La/ Sr/Cs/La/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/Tm/Li/Cs Sr/Tm/Li/Cs/ Sr/Tm/Li/Cs/ Sr/Tm/Li/Cs/ Sr/Tm/Li/Cs/ Sr/Tm/Li/Cs/ Sr/Tm/Li/Cs/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Zn/K Zn/K/ Zn/K/ Zn/K/ Zn/K/ Zn/K/ Zn/K/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Zr/Cs/K/La Zr/Cs/K/La/ Zr/Cs/K/La/ Zr/Cs/K/La/ Zr/Cs/K/La/ Zr/Cs/K/La/ Zr/Cs/K/La/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Rb/Ca/In/Ni Rb/Ca/In/Ni/ Rb/Ca/In/Ni/ Rb/Ca/In/Ni/ Rb/Ca/In/Ni/ Rb/Ca/In/Ni/ Rb/Ca/In/Ni/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/Ho/Tm Sr/Ho/Tm/ Sr/Ho/Tm/ Sr/Ho/Tm/ Sr/Ho/Tm/ Sr/Ho/Tm/ Sr/Ho/Tm/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ La/Nd/S La/Nd/S/ La/Nd/S/ La/Nd/S/ La/Nd/S/ La/Nd/S/ La/Nd/S/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/Hf/Rb Sr/Hf/Rb/ Sr/Hf/Rb/ Sr/Hf/Rb/ Sr/Hf/Rb/ Sr/Hf/Rb/ Sr/Hf/Rb/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Li/Rb/Ca Li/Rb/Ca/ Li/Rb/Ca/ Li/Rb/Ca/ Li/Rb/Ca/ Li/Rb/Ca/ Li/Rb/Ca/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Li/K Li/K/ Li/K/ Li/K/ Li/K/ Li/K/ Li/K/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Tm/Lu/Ta/P Tm/Lu/Ta/P/ Tm/Lu/Ta/P/ Tm/Lu/Ta/P/ Tm/Lu/Ta/P/ Tm/Lu/Ta/P/ Tm/Lu/Ta/P/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Rb/Ca/Dy/P Rb/Ca/Dy/P/ Rb/Ca/Dy/P/ Rb/Ca/Dy/P/ Rb/Ca/Dy/P/ Rb/Ca/Dy/P/ Rb/Ca/Dy/P/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Mg/La/Yb/Zn Mg/La/Yb/Zn/ Mg/La/Yb/Zn/ Mg/La/Yb/Zn/ Mg/La/Yb/Zn/ Mg/La/Yb/Zn/ Mg/La/Yb/Zn/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Rb/Sr/Lu Rb/Sr/Lu/ Rb/Sr/Lu/ Rb/Sr/Lu/ Rb/Sr/Lu/ Rb/Sr/Lu/ Rb/Sr/Lu/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Na/Sr/Lu/Nb Na/Sr/Lu/Nb/ Na/Sr/Lu/Nb/ Na/Sr/Lu/Nb/ Na/Sr/Lu/Nb/ Na/Sr/Lu/Nb/ Na/Sr/Lu/Nb/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Na/Eu/Hf Na/Eu/Hf/ Na/Eu/Hf/ Na/Eu/Hf/ Na/Eu/Hf/ Na/Eu/Hf/ Na/Eu/Hf/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Dy/Rb/Gd Dy/Rb/Gd/ Dy/Rb/Gd/ Dy/Rb/Gd/ Dy/Rb/Gd/ Dy/Rb/Gd/ Dy/Rb/Gd/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Na/Pt/Bi Na/Pt/Bi/ Na/Pt/Bi/ Na/Pt/Bi/ Na/Pt/Bi/ Na/Pt/Bi/ Na/Pt/Bi/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Rb/Hf Rb/Hf/ Rb/Hf/ Rb/Hf/ Rb/Hf/ Rb/Hf/ Rb/Hf/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Ca/Cs Ca/Cs/ Ca/Cs/ Ca/Cs/ Ca/Cs/ Ca/Cs/ Ca/Cs/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Ca/Mg/Na Ca/Mg/Na/ Ca/Mg/Na/ Ca/Mg/Na/ Ca/Mg/Na/ Ca/Mg/Na/ Ca/Mg/Na/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Hf/Bi Hf/Bi/ Hf/Bi/ Hf/Bi/ Hf/Bi/ Hf/Bi/ Hf/Bi/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/Sn Sr/Sn/ Sr/Sn/ Sr/Sn/ Sr/Sn/ Sr/Sn/ Sr/Sn/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/W Sr/W/ Sr/W/ Sr/W/ Sr/W/ Sr/W/ Sr/W/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/Nb Sr/Nb/ Sr/Nb/ Sr/Nb/ Sr/Nb/ Sr/Nb/ Sr/Nb/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Zr/W Zr/W/ Zr/W/ Zr/W/ Zr/W/ Zr/W/ Zr/W/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/Hf/K Sr/Hf/K/ Sr/Hf/K/ Sr/Hf/K/ Sr/Hf/K/ Sr/Hf/K/ Sr/Hf/K/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Y/W Y/W/ Y/W/ Y/W/ Y/W/ Y/W/ Y/W/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Na/W Na/W/ Na/W/ Na/W/ Na/W/ Na/W/ Na/W/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Bi/W Bi/W/ Bi/W/ Bi/W/ Bi/W/ Bi/W/ Bi/W/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Bi/Cs Bi/Cs/ Bi/Cs/ Bi/Cs/ Bi/Cs/ Bi/Cs/ Bi/Cs/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Bi/Ca Bi/Ca/ Bi/Ca/ Bi/Ca/ Bi/Ca/ Bi/Ca/ Bi/Ca/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Bi/Sn Bi/Sn/ Bi/Sn/ Bi/Sn/ Bi/Sn/ Bi/Sn/ Bi/Sn/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Bi/Sb Bi/Sb/ Bi/Sb/ Bi/Sb/ Bi/Sb/ Bi/Sb/ Bi/Sb/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Ge/Hf Ge/Hf/ Ge/Hf/ Ge/Hf/ Ge/Hf/ Ge/Hf/ Ge/Hf/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Hf/Sm Hf/Sm/ Hf/Sm/ Hf/Sm/ Hf/Sm/ Hf/Sm/ Hf/Sm/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sb/Ag Sb/Ag/ Sb/Ag/ Sb/Ag/ Sb/Ag/ Sb/Ag/ Sb/Ag/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sb/Bi Sb/Bi/ Sb/Bi/ Sb/Bi/ Sb/Bi/ Sb/Bi/ Sb/Bi/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sb/Au Sb/Au/ Sb/Au/ Sb/Au/ Sb/Au/ Sb/Au/ Sb/Au/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/Zr Sr/Zr/ Sr/Zr/ Sr/Zr/ Sr/Zr/ Sr/Zr/ Sr/Zr/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sb/Sm Sb/Sm/ Sb/Sm/ Sb/Sm/ Sb/Sm/ Sb/Sm/ Sb/Sm/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sb/Sr Sb/Sr/ Sb/Sr/ Sb/Sr/ Sb/Sr/ Sb/Sr/ Sb/Sr/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sb/W Sb/W/ Sb/W/ Sb/W/ Sb/W/ Sb/W/ Sb/W/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sb/Hf Sb/Hf/ Sb/Hf/ Sb/Hf/ Sb/Hf/ Sb/Hf/ Sb/Hf/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sb/Yb Sb/Yb/ Sb/Yb/ Sb/Yb/ Sb/Yb/ Sb/Yb/ Sb/Yb/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sb/Sn Sb/Sn/ Sb/Sn/ Sb/Sn/ Sb/Sn/ Sb/Sn/ Sb/Sn/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Yb/Au Yb/Au/ Yb/Au/ Yb/Au/ Yb/Au/ Yb/Au/ Yb/Au/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Yb/Ta Yb/Ta/ Yb/Ta/ Yb/Ta/ Yb/Ta/ Yb/Ta/ Yb/Ta/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Yb/W Yb/W/ Yb/W/ Yb/W/ Yb/W/ Yb/W/ Yb/W/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Yb/Sr Yb/Sr/ Yb/Sr/ Yb/Sr/ Yb/Sr/ Yb/Sr/ Yb/Sr/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Yb/Pb Yb/Pb/ Yb/Pb/ Yb/Pb/ Yb/Pb/ Yb/Pb/ Yb/Pb/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Yb/W Yb/W/ Yb/W/ Yb/W/ Yb/W/ Yb/W/ Yb/W/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Yb/Ag Yb/Ag/ Yb/Ag/ Yb/Ag/ Yb/Ag/ Yb/Ag/ Yb/Ag/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Au/Sr Au/Sr/ Au/Sr/ Au/Sr/ Au/Sr/ Au/Sr/ Au/Sr/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ W/Ge W/Ge/ W/Ge/ W/Ge/ W/Ge/ W/Ge/ W/Ge/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Ta/Sr Ta/Sr/ Ta/Sr/ Ta/Sr/ Ta/Sr/ Ta/Sr/ Ta/Sr/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Ta/Hf Ta/Hf/ Ta/Hf/ Ta/Hf/ Ta/Hf/ Ta/Hf/ Ta/Hf/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ W/Au W/Au/ W/Au/ W/Au/ W/Au/ W/Au/ W/Au/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/Tb Sr/Tb/ Sr/Tb/ Sr/Tb/ Sr/Tb/ Sr/Tb/ Sr/Tb/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Ca/W Ca/W/ Ca/W/ Ca/W/ Ca/W/ Ca/W/ Ca/W/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Au/Re Au/Re/ Au/Re/ Au/Re/ Au/Re/ Au/Re/ Au/Re/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sm/Li Sm/Li/ Sm/Li/ Sm/Li/ Sm/Li/ Sm/Li/ Sm/Li/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ La/K La/K/ La/K/ La/K/ La/K/ La/K/ La/K/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Zn/Cs Zn/Cs/ Zn/Cs/ Zn/Cs/ Zn/Cs/ Zn/Cs/ Zn/Cs/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Na/K/Mg Na/K/Mg/ Na/K/Mg/ Na/K/Mg/ Na/K/Mg/ Na/K/Mg/ Na/K/Mg/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Zr/Cs Zr/Cs/ Zr/Cs/ Zr/Cs/ Zr/Cs/ Zr/Cs/ Zr/Cs/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Ca/Ce Ca/Ce/ Ca/Ce/ Ca/Ce/ Ca/Ce/ Ca/Ce/ Ca/Ce/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Na/Li/Cs Na/Li/Cs/ Na/Li/Cs/ Na/Li/Cs/ Na/Li/Cs/ Na/Li/Cs/ Na/Li/Cs/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Li/Sr Li/Sr/ Li/Sr/ Li/Sr/ Li/Sr/ Li/Sr/ Li/Sr/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ La/Dy/K La/Dy/K/ La/Dy/K/ La/Dy/K/ La/Dy/K/ La/Dy/K/ La/Dy/K/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Dy/K Dy/K/ Dy/K/ Dy/K/ Dy/K/ Dy/K/ Dy/K/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ La/Mg La/Mg/ La/Mg/ La/Mg/ La/Mg/ La/Mg/ La/Mg/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Na/Nd/In/K Na/Nd/In/K/ Na/Nd/In/K/ Na/Nd/In/K/ Na/Nd/In/K/ Na/Nd/In/K/ Na/Nd/In/K/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ In/Sr In/Sr/ In/Sr/ In/Sr/ In/Sr/ In/Sr/ In/Sr/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/Cs Sr/Cs/ Sr/Cs/ Sr/Cs/ Sr/Cs/ Sr/Cs/ Sr/Cs/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/Ce Sr/Ce/ Sr/Ce/ Sr/Ce/ Sr/Ce/ Sr/Ce/ Sr/Ce/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Rb/Ga/Tm/Cs Rb/Ga/Tm/Cs/ Rb/Ga/Tm/Cs/ Rb/Ga/Tm/Cs/ Rb/Ga/Tm/Cs/ Rb/Ga/Tm/Cs/ Rb/Ga/Tm/Cs/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Ga/Cs Ga/Cs/ Ga/Cs/ Ga/Cs/ Ga/Cs/ Ga/Cs/ Ga/Cs/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ K/La/Zr/Ag K/La/Zr/Ag/ K/La/Zr/Ag/ K/La/Zr/Ag/ K/La/Zr/Ag/ K/La/Zr/Ag/ K/La/Zr/Ag/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Lu/Fe Lu/Fe/ Lu/Fe/ Lu/Fe/ Lu/Fe/ Lu/Fe/ Lu/Fe/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/Tm Sr/Tm/ Sr/Tm/ Sr/Tm/ Sr/Tm/ Sr/Tm/ Sr/Tm/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ La/Dy La/Dy/ La/Dy/ La/Dy/ La/Dy/ La/Dy/ La/Dy/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sm/Li/Sr Sm/Li/Sr/ Sm/Li/Sr/ Sm/Li/Sr/ Sm/Li/Sr/ Sm/Li/Sr/ Sm/Li/Sr/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/Zr/K Sr/Zr/K/ Sr/Zr/K/ Sr/Zr/K/ Sr/Zr/K/ Sr/Zr/K/ Sr/Zr/K/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Mg/K Mg/K/ Mg/K/ Mg/K/ Mg/K/ Mg/K/ Mg/K/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Li/Rb/Ga Li/Rb/Ga/ Li/Rb/Ga/ Li/Rb/Ga/ Li/Rb/Ga/ Li/Rb/Ga/ Li/Rb/Ga/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Li/Cs/Tm Li/Cs/Tm/ Li/Cs/Tm/ Li/Cs/Tm/ Li/Cs/Tm/ Li/Cs/Tm/ Li/Cs/Tm/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Zr/K Zr/K/ Zr/K/ Zr/K/ Zr/K/ Zr/K/ Zr/K/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Li/Cs Li/Cs/ Li/Cs/ Li/Cs/ Li/Cs/ Li/Cs/ Li/Cs/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Li/K/La Li/K/La/ Li/K/La/ Li/K/La/ Li/K/La/ Li/K/La/ Li/K/La/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Ce/Zr/La Ce/Zr/La/ Ce/Zr/La/ Ce/Zr/La/ Ce/Zr/La/ Ce/Zr/La/ Ce/Zr/La/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Ca/Al/La Ca/Al/La/ Ca/Al/La/ Ca/Al/La/ Ca/Al/La/ Ca/Al/La/ Ca/Al/La/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/Zn/La Sr/Zn/La/ Sr/Zn/La/ Sr/Zn/La/ Sr/Zn/La/ Sr/Zn/La/ Sr/Zn/La/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/Cs/Zn Sr/Cs/Zn/ Sr/Cs/Zn/ Sr/Cs/Zn/ Sr/Cs/Zn/ Sr/Cs/Zn/ Sr/Cs/Zn/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sm/Cs Sm/Cs/ Sm/Cs/ Sm/Cs/ Sm/Cs/ Sm/Cs/ Sm/Cs/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ In/K In/K/ In/K/ In/K/ In/K/ In/K/ In/K/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Ho/Cs/Li/La Ho/Cs/Li/La/ Ho/Cs/Li/La/ Ho/Cs/Li/La/ Ho/Cs/Li/La/ Ho/Cs/Li/La/ Ho/Cs/Li/La/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Cs/La/Na Cs/La/Na/ Cs/La/Na/ Cs/La/Na/ Cs/La/Na/ Cs/La/Na/ Cs/La/Na/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ La/S/Sr La/S/Sr/ La/S/Sr/ La/S/Sr/ La/S/Sr/ La/S/Sr/ La/S/Sr/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ K/La/Zr/Ag K/La/Zr/Ag/ K/La/Zr/Ag/ K/La/Zr/Ag/ K/La/Zr/Ag/ K/La/Zr/Ag/ K/La/Zr/Ag/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Lu/Tl Lu/Tl/ Lu/Tl/ Lu/Tl/ Lu/Tl/ Lu/Tl/ Lu/Tl/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Pr/Zn Pr/Zn/ Pr/Zn/ Pr/Zn/ Pr/Zn/ Pr/Zn/ Pr/Zn/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Rb/Sr/La Rb/Sr/La/ Rb/Sr/La/ Rb/Sr/La/ Rb/Sr/La/ Rb/Sr/La/ Rb/Sr/La/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/Ce/K Sr/Ce/K/ Sr/Ce/K/ Sr/Ce/K/ Sr/Ce/K/ Sr/Ce/K/ Sr/Ce/K/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Na/Sr/Eu/Ca Na/Sr/Eu/Ca/ Na/Sr/Eu/Ca/ Na/Sr/Eu/Ca/ Na/Sr/Eu/Ca/ Na/Sr/Eu/Ca/ Na/Sr/Eu/Ca/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ K/Cs/Sr/La K/Cs/Sr/La/ K/Cs/Sr/La/ K/Cs/Sr/La/ K/Cs/Sr/La/ K/Cs/Sr/La/ K/Cs/Sr/La/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Na/Sr/Lu Na/Sr/Lu/ Na/Sr/Lu/ Na/Sr/Lu/ Na/Sr/Lu/ Na/Sr/Lu/ Na/Sr/Lu/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/Eu/Dy Sr/Eu/Dy/ Sr/Eu/Dy/ Sr/Eu/Dy/ Sr/Eu/Dy/ Sr/Eu/Dy/ Sr/Eu/Dy/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Lu/Nb Lu/Nb/ Lu/Nb/ Lu/Nb/ Lu/Nb/ Lu/Nb/ Lu/Nb/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ La/Dy/Gd La/Dy/Gd/ La/Dy/Gd/ La/Dy/Gd/ La/Dy/Gd/ La/Dy/Gd/ La/Dy/Gd/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Na/Mg/Tl/P Na/Mg/Tl/P/ Na/Mg/Tl/P/ Na/Mg/Tl/P/ Na/Mg/Tl/P/ Na/Mg/Tl/P/ Na/Mg/Tl/P/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Na/Pt Na/Pt/ Na/Pt/ Na/Pt/ Na/Pt/ Na/Pt/ Na/Pt/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Gd/Li/K Gd/Li/K/ Gd/Li/K/ Gd/Li/K/ Gd/Li/K/ Gd/Li/K/ Gd/Li/K/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Rb/K/Lu Rb/K/Lu/ Rb/K/Lu/ Rb/K/Lu/ Rb/K/Lu/ Rb/K/Lu/ Rb/K/Lu/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/La/Dy/S Sr/La/Dy/S/ Sr/La/Dy/S/ Sr/La/Dy/S/ Sr/La/Dy/S/ Sr/La/Dy/S/ Sr/La/Dy/S/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Na/Ce/Co Na/Ce/Co/ Na/Ce/Co/ Na/Ce/Co/ Na/Ce/Co/ Na/Ce/Co/ Na/Ce/Co/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Na/Ce Na/Ce/ Na/Ce/ Na/Ce/ Na/Ce/ Na/Ce/ Na/Ce/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Na/Ga/Gd/Al Na/Ga/Gd/Al/ Na/Ga/Gd/Al/ Na/Ga/Gd/Al/ Na/Ga/Gd/Al/ Na/Ga/Gd/Al/ Na/Ga/Gd/Al/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Ba/Rh/Ta Ba/Rh/Ta/ Ba/Rh/Ta/ Ba/Rh/Ta/ Ba/Rh/Ta/ Ba/Rh/Ta/ Ba/Rh/Ta/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Ba/Ta Ba/Ta/ Ba/Ta/ Ba/Ta/ Ba/Ta/ Ba/Ta/ Ba/Ta/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Na/Al/Bi Na/Al/Bi/ Na/Al/Bi/ Na/Al/Bi/ Na/Al/Bi/ Na/Al/Bi/ Na/Al/Bi/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Cs/Eu/S Cs/Eu/S/ Cs/Eu/S/ Cs/Eu/S/ Cs/Eu/S/ Cs/Eu/S/ Cs/Eu/S/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sm/Tm/Yb/Fe Sm/Tm/Yb/Fe/ Sm/Tm/Yb/Fe/ Sm/Tm/Yb/Fe/ Sm/Tm/Yb/Fe/ Sm/Tm/Yb/Fe/ Sm/Tm/Yb/Fe/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sm/Tm/Yb Sm/Tm/Yb/ Sm/Tm/Yb/ Sm/Tm/Yb/ Sm/Tm/Yb/ Sm/Tm/Yb/ Sm/Tm/Yb/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Hf/Zr/Ta Hf/Zr/Ta/ Hf/Zr/Ta/ Hf/Zr/Ta/ Hf/Zr/Ta/ Hf/Zr/Ta/ Hf/Zr/Ta/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/Tb/K Sr/Tb/K/ Sr/Tb/K/ Sr/Tb/K/ Sr/Tb/K/ Sr/Tb/K/ Sr/Tb/K/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Rb/Gd/Li/K Rb/Gd/Li/K/ Rb/Gd/Li/K/ Rb/Gd/Li/K/ Rb/Gd/Li/K/ Rb/Gd/Li/K/ Rb/Gd/Li/K/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Gd/Ho/Al/P Gd/Ho/Al/P/ Gd/Ho/Al/P/ Gd/Ho/Al/P/ Gd/Ho/Al/P/ Gd/Ho/Al/P/ Gd/Ho/Al/P/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Na/Ca/Lu Na/Ca/Lu/ Na/Ca/Lu/ Na/Ca/Lu/ Na/Ca/Lu/ Na/Ca/Lu/ Na/Ca/Lu/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Cu/Sn Cu/Sn/ Cu/Sn/ Cu/Sn/ Cu/Sn/ Cu/Sn/ Cu/Sn/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Ag/Au Ag/Au/ Ag/Au/ Ag/Au/ Ag/Au/ Ag/Au/ Ag/Au/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Al/Bi Al/Bi/ Al/Bi/ Al/Bi/ Al/Bi/ Al/Bi/ Al/Bi/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Al/Mo Al/Mo/ Al/Mo/ Al/Mo/ Al/Mo/ Al/Mo/ Al/Mo/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Al/Nb Al/Nb/ Al/Nb/ Al/Nb/ Al/Nb/ Al/Nb/ Al/Nb/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Au/Pt Au/Pt/ Au/Pt/ Au/Pt/ Au/Pt/ Au/Pt/ Au/Pt/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Ga/Bi Ga/Bi/ Ga/Bi/ Ga/Bi/ Ga/Bi/ Ga/Bi/ Ga/Bi/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Mg/W Mg/W/ Mg/W/ Mg/W/ Mg/W/ Mg/W/ Mg/W/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Pb/Au Pb/Au/ Pb/Au/ Pb/Au/ Pb/Au/ Pb/Au/ Pb/Au/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sn/Mg Sn/Mg/ Sn/Mg/ Sn/Mg/ Sn/Mg/ Sn/Mg/ Sn/Mg/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Zn/Bi Zn/Bi/ Zn/Bi/ Zn/Bi/ Zn/Bi/ Zn/Bi/ Zn/Bi/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/Ta Sr/Ta/ Sr/Ta/ Sr/Ta/ Sr/Ta/ Sr/Ta/ Sr/Ta/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Na Na/ Na/ Na/ Na/ Na/ Na/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr Sr/ Sr/ Sr/ Sr/ Sr/ Sr/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Ca Ca/ Ca/ Ca/ Ca/ Ca/ Ca/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Yb Yb/ Yb/ Yb/ Yb/ Yb/ Yb/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Cs Cs/ Cs/ Cs/ Cs/ Cs/ Cs/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sb Sb/ Sb/ Sb/ Sb/ Sb/ Sb/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Gd/Ho Gd/Ho/ Gd/Ho/ Gd/Ho/ Gd/Ho/ Gd/Ho/ Gd/Ho/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Zr/Bi Zr/Bi/ Zr/Bi/ Zr/Bi/ Zr/Bi/ Zr/Bi/ Zr/Bi/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Ho/Sr Ho/Sr/ Ho/Sr/ Ho/Sr/ Ho/Sr/ Ho/Sr/ Ho/Sr/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Gd/Ho/Sr Gd/Ho/Sr/ Gd/Ho/Sr/ Gd/Ho/Sr/ Gd/Ho/Sr/ Gd/Ho/Sr/ Gd/Ho/Sr/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Ca/Sr Ca/Sr/ Ca/Sr/ Ca/Sr/ Ca/Sr/ Ca/Sr/ Ca/Sr/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Ca/Sr/W Ca/Sr/W/ Ca/Sr/W/ Ca/Sr/W/ Ca/Sr/W/ Ca/Sr/W/ Ca/Sr/W/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Na/Zr/Eu/Tm Na/Zr/Eu/Tm/ Na/Zr/Eu/Tm/ Na/Zr/Eu/Tm/ Na/Zr/Eu/Tm/ Na/Zr/Eu/Tm/ Na/Zr/Eu/Tm/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/Ho/Tm/Na Sr/Ho/Tm/Na/ Sr/Ho/Tm/Na/ Sr/Ho/Tm/Na/ Sr/Ho/Tm/Na/ Sr/Ho/Tm/Na/ Sr/Ho/Tm/Na/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/Pb Sr/Pb/ Sr/Pb/ Sr/Pb/ Sr/Pb/ Sr/Pb/ Sr/Pb/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/W/Li Sr/W/Li/ Sr/W/Li/ Sr/W/Li/ Sr/W/Li/ Sr/W/Li/ Sr/W/Li/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Ca/Sr/W Ca/Sr/W/ Ca/Sr/W/ Ca/Sr/W/ Ca/Sr/W/ Ca/Sr/W/ Ca/Sr/W/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/Hf Sr/Hf/ Sr/Hf/ Sr/Hf/ Sr/Hf/ Sr/Hf/ Sr/Hf/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Au/Re Au/Re/ Au/Re/ Au/Re/ Au/Re/ Au/Re/ Au/Re/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/W Sr/W/ Sr/W/ Sr/W/ Sr/W/ Sr/W/ Sr/W/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ La/Nd La/Nd/ La/Nd/ La/Nd/ La/Nd/ La/Nd/ La/Nd/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ La/Sm La/Sm/ La/Sm/ La/Sm/ La/Sm/ La/Sm/ La/Sm/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ La/Ce La/Ce/ La/Ce/ La/Ce/ La/Ce/ La/Ce/ La/Ce/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ La/Sr La/Sr/ La/Sr/ La/Sr/ La/Sr/ La/Sr/ La/Sr/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ La/Nd/Sr La/Nd/Sr/ La/Nd/Sr/ La/Nd/Sr/ La/Nd/Sr/ La/Nd/Sr/ La/Nd/Sr/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ La/Bi/Sr La/Bi/Sr/ La/Bi/Sr/ La/Bi/Sr/ La/Bi/Sr/ La/Bi/Sr/ La/Bi/Sr/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ La/Ce/Nd/Sr La/Ce/Nd/Sr/ La/Ce/Nd/Sr/ La/Ce/Nd/Sr/ La/Ce/Nd/Sr/ La/Ce/Nd/Sr/ La/Ce/Nd/Sr/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ La/Bi/Ce/Nd/Sr La/Bi/Ce/Nd/Sr/ La/Bi/Ce/Nd/Sr/ La/Bi/Ce/Nd/Sr/ La/Bi/Ce/Nd/Sr/ La/Bi/Ce/Nd/Sr/ La/Bi/Ce/Nd/Sr/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Eu/Gd Eu/Gd/ Eu/Gd/ Eu/Gd/ Eu/Gd/ Eu/Gd/ Eu/Gd/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Ca/Na Ca/Na/ Ca/Na/ Ca/Na/ Ca/Na/ Ca/Na/ Ca/Na/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Eu/Sm Eu/Sm/ Eu/Sm/ Eu/Sm/ Eu/Sm/ Eu/Sm/ Eu/Sm/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Eu/Sr Eu/Sr/ Eu/Sr/ Eu/Sr/ Eu/Sr/ Eu/Sr/ Eu/Sr/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Mg/Sr Mg/Sr/ Mg/Sr/ Mg/Sr/ Mg/Sr/ Mg/Sr/ Mg/Sr/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Ce/Mg Ce/Mg/ Ce/Mg/ Ce/Mg/ Ce/Mg/ Ce/Mg/ Ce/Mg/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Gd/Sm Gd/Sm/ Gd/Sm/ Gd/Sm/ Gd/Sm/ Gd/Sm/ Gd/Sm/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Au/Pb Au/Pb/ Au/Pb/ Au/Pb/ Au/Pb/ Au/Pb/ Au/Pb/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Bi/Hf Bi/Hf/ Bi/Hf/ Bi/Hf/ Bi/Hf/ Bi/Hf/ Bi/Hf/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Rb/S Rb/S/ Rb/S/ Rb/S/ Rb/S/ Rb/S/ Rb/S/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Sr/Nd Sr/Nd/ Sr/Nd/ Sr/Nd/ Sr/Nd/ Sr/Nd/ Sr/Nd/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Eu/Y Eu/Y/ Eu/Y/ Eu/Y/ Eu/Y/ Eu/Y/ Eu/Y/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Mg/Nd Mg/Nd/ Mg/Nd/ Mg/Nd/ Mg/Nd/ Mg/Nd/ Mg/Nd/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ La/Mg La/Mg/ La/Mg/ La/Mg/ La/Mg/ La/Mg/ La/Mg/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Mg/Nd/Fe Mg/Nd/Fe/ Mg/Nd/Fe/ Mg/Nd/Fe/ Mg/Nd/Fe/ Mg/Nd/Fe/ Mg/Nd/Fe/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ Rb/Sr Rb/Sr/ Rb/Sr/ Rb/Sr/ Rb/Sr/ Rb/Sr/ Rb/Sr/ La_(4−X)Nd_(X)O₆ LaNd₃O₆ La_(1.5)Nd_(2.5)O₆ La_(2.5)Nd_(1.5)O₆ La_(3.2)Nd_(0.8)O₆ La_(3.5)Nd_(0.5)O₆ *x is a number ranging from greater than 0 to less than 4

TABLE 11 NANOWIRES (NW) DOPED WITH SPECIFIC DOPANTS (DOP) NW Dop La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Eu/Na Eu/Na/ Eu/Na/ Eu/Na/ Eu/Na/ Eu/Na/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/Na Sr/Na/ Sr/Na/ Sr/Na/ Sr/Na/ Sr/Na/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Na/Zr/Eu/Ca Na/Zr/Eu/Ca/ Na/Zr/Eu/Ca/ Na/Zr/Eu/Ca/ Na/Zr/Eu/Ca/ Na/Zr/Eu/Ca/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—Laa Ce—La Mg/Na Mg/Na/ Mg/Na/ Mg/Na/ Mg/Na/ Mg/Na/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/Sm/Ho/Tm Sr/Sm/Ho/Tm/ Sr/Sm/Ho/Tm/ Sr/Sm/Ho/Tm/ Sr/Sm/Ho/Tm/ Sr/Sm/Ho/Tm/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/W Sr/W/ Sr/W/ Sr/W/ Sr/W/ Sr/W/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Mg/La/K Mg/La/K/ Mg/La/K/ Mg/La/K/ Mg/La/K/ Mg/La/K/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Na/K/Mg/Tm Na/K/Mg/Tm/ Na/K/Mg/Tm/ Na/K/Mg/Tm/ Na/K/Mg/Tm/ Na/K/Mg/Tm/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Na/Dy/K Na/Dy/K/ Na/Dy/K/ Na/Dy/K/ Na/Dy/K/ Na/Dy/K/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Na/La/Dy Na/La/Dy/ Na/La/Dy/ Na/La/Dy/ Na/La/Dy/ Na/La/Dy/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Na/La/Eu Na/La/Eu/ Na/La/Eu/ Na/La/Eu/ Na/La/Eu/ Na/La/Eu/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Na/La/Eu/In Na/La/Eu/In/ Na/La/Eu/In/ Na/La/Eu/In/ Na/La/Eu/In/ Na/La/Eu/In/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Na/La/K Na/La/K/ Na/La/K/ Na/La/K/ Na/La/K/ Na/La/K/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Na/La/Li/Cs Na/La/Li/Cs/ Na/La/Li/Cs/ Na/La/Li/Cs/ Na/La/Li/Cs/ Na/La/Li/Cs/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La K/La K/La/ K/La/ K/La/ K/La/ K/La/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La K/La/S K/La/S/ K/La/S/ K/La/S/ K/La/S/ K/La/S/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La K/Na K/Na/ K/Na/ K/Na/ K/Na/ K/Na/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Li/Cs Li/Cs/ Li/Cs/ Li/Cs/ Li/Cs/ Li/Cs/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Li/Cs/La Li/Cs/La/ Li/Cs/La/ Li/Cs/La/ Li/Cs/La/ Li/Cs/La/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/Pr/K Sr/Pr/K/ Sr/Pr/K/ Sr/Pr/K/ Sr/Pr/K/ Sr/Pr/K/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Li/Cs/La/Tm Li/Cs/La/Tm/ Li/Cs/La/Tm/ Li/Cs/La/Tm/ Li/Cs/La/Tm/ Li/Cs/La/Tm/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Li/Cs/Sr/Tm Li/Cs/Sr/Tm/ Li/Cs/Sr/Tm/ Li/Cs/Sr/Tm/ Li/Cs/Sr/Tm/ Li/Cs/Sr/Tm/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Li/Sr/Cs Li/Sr/Cs/ Li/Sr/Cs/ Li/Sr/Cs/ Li/Sr/Cs/ Li/Sr/Cs/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Li/Sr/Zn/K Li/Sr/Zn/K/ Li/Sr/Zn/K/ Li/Sr/Zn/K/ Li/Sr/Zn/K/ Li/Sr/Zn/K/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Li/Ga/Cs Li/Ga/Cs/ Li/Ga/Cs/ Li/Ga/Cs/ Li/Ga/Cs/ Li/Ga/Cs/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Li/K/Sr/La Li/K/Sr/La/ Li/K/Sr/La/ Li/K/Sr/La/ Li/K/Sr/La/ Li/K/Sr/La/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Li/Na Li/Na/ Li/Na/ Li/Na/ Li/Na/ Li/Na/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Li/Na/Rb/Ga Li/Na/Rb/Ga/ Li/Na/Rb/Ga/ Li/Na/Rb/Ga/ Li/Na/Rb/Ga/ Li/Na/Rb/Ga/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Li/Na/Sr Li/Na/Sr/ Li/Na/Sr/ Li/Na/Sr/ Li/Na/Sr/ Li/Na/Sr/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Li/Na/Sr/La Li/Na/Sr/La/ Li/Na/Sr/La/ Li/Na/Sr/La/ Li/Na/Sr/La/ Li/Na/Sr/La/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Li/Sm/Cs Li/Sm/Cs/ Li/Sm/Cs/ Li/Sm/Cs/ Li/Sm/Cs/ Li/Sm/Cs/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Ba/Sm/Yb/S Ba/Sm/Yb/S/ Ba/Sm/Yb/S/ Ba/Sm/Yb/S/ Ba/Sm/Yb/S/ Ba/Sm/Yb/S/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Ba/Tm/K/La Ba/Tm/K/La/ Ba/Tm/K/La/ Ba/Tm/K/La/ Ba/Tm/K/La/ Ba/Tm/K/La/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Ba/Tm/Zn/K Ba/Tm/Zn/K/ Ba/Tm/Zn/K/ Ba/Tm/Zn/K/ Ba/Tm/Zn/K/ Ba/Tm/Zn/K/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/Tb/K Sr/Tb/K/ Sr/Tb/K/ Sr/Tb/K/ Sr/Tb/K/ Sr/Tb/K/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La C + s/K/La Cs/K/La/ Cs/K/La/ Cs/K/La/ Cs/K/La/ Cs/K/La/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Cs/La/Tm/Na Cs/La/Tm/Na/ Cs/La/Tm/Na/ Cs/La/Tm/Na/ Cs/La/Tm/Na/ Cs/La/Tm/Na/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Cs/Li/K/La Cs/Li/K/La/ Cs/Li/K/La/ Cs/Li/K/La/ Cs/Li/K/La/ Cs/Li/K/La/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sm/Li/Sr/Cs Sm/Li/Sr/Cs/ Sm/Li/Sr/Cs/ Sm/Li/Sr/Cs/ Sm/Li/Sr/Cs/ Sm/Li/Sr/Cs/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/Cs/La Sr/Cs/La/ Sr/Cs/La/ Sr/Cs/La/ Sr/Cs/La/ Sr/Cs/La/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/Tm/Li/Cs Sr/Tm/Li/Cs/ Sr/Tm/Li/Cs/ Sr/Tm/Li/Cs/ Sr/Tm/Li/Cs/ Sr/Tm/Li/Cs/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Zn/K Zn/K/ Zn/K/ Zn/K/ Zn/K/ Zn/K/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Zr/Cs/K/La Zr/Cs/K/La/ Zr/Cs/K/La/ Zr/Cs/K/La/ Zr/Cs/K/La/ Zr/Cs/K/La/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Rb/Ca/In/Ni Rb/Ca/In/Ni/ Rb/Ca/In/Ni/ Rb/Ca/In/Ni/ Rb/Ca/In/Ni/ Rb/Ca/In/Ni/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/Ho/Tm Sr/Ho/Tm/ Sr/Ho/Tm/ Sr/Ho/Tm/ Sr/Ho/Tm/ Sr/Ho/Tm/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La La/Nd/S La/Nd/S/ La/Nd/S/ La/Nd/S/ La/Nd/S/ La/Nd/S/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Li/Rb/Ca Li/Rb/Ca/ Li/Rb/Ca/ Li/Rb/Ca/ Li/Rb/Ca/ Li/Rb/Ca/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Li/K Li/K/ Li/K/ Li/K/ Li/K/ Li/K/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Tm/Lu/Ta/P Tm/Lu/Ta/P/ Tm/Lu/Ta/P/ Tm/Lu/Ta/P/ Tm/Lu/Ta/P/ Tm/Lu/Ta/P/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Rb/Ca/Dy/P Rb/Ca/Dy/P/ Rb/Ca/Dy/P/ Rb/Ca/Dy/P/ Rb/Ca/Dy/P/ Rb/Ca/Dy/P/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Mg/La/Yb/Zn Mg/La/Yb/Zn/ Mg/La/Yb/Zn/ Mg/La/Yb/Zn/ Mg/La/Yb/Zn/ Mg/La/Yb/Zn/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Rb/Sr/Lu Rb/Sr/Lu/ Rb/Sr/Lu/ Rb/Sr/Lu/ Rb/Sr/Lu/ Rb/Sr/Lu/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/B Sr/B/ Sr/B/ Sr/B/ Sr/B/ Sr/B/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Na/Sr/Lu/Nb Na/Sr/Lu/Nb/ Na/Sr/Lu/Nb/ Na/Sr/Lu/Nb/ Na/Sr/Lu/Nb/ Na/Sr/Lu/Nb/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Na/Eu/Hf Na/Eu/Hf/ Na/Eu/Hf/ Na/Eu/Hf/ Na/Eu/Hf/ Na/Eu/Hf/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Dy/Rb/Gd Dy/Rb/Gd/ Dy/Rb/Gd/ Dy/Rb/Gd/ Dy/Rb/Gd/ Dy/Rb/Gd/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Na/Pt/Bi Na/Pt/Bi/ Na/Pt/Bi/ Na/Pt/Bi/ Na/Pt/Bi/ Na/Pt/Bi/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Rb/Hf Rb/Hf/ Rb/Hf/ Rb/Hf/ Rb/Hf/ Rb/Hf/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Ca/Cs Ca/Cs/ Ca/Cs/ Ca/Cs/ Ca/Cs/ Ca/Cs/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Ca/Mg/Na Ca/Mg/Na/ Ca/Mg/Na/ Ca/Mg/Na/ Ca/Mg/Na/ Ca/Mg/Na/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Hf/Bi Hf/Bi/ Hf/Bi/ Hf/Bi/ Hf/Bi/ Hf/Bi/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/Sn Sr/Sn/ Sr/Sn/ Sr/Sn/ Sr/Sn/ Sr/Sn/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/W Sr/W/ Sr/W/ Sr/W/ Sr/W/ Sr/W/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/Nb Sr/Nb/ Sr/Nb/ Sr/Nb/ Sr/Nb/ Sr/Nb/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Zr/W Zr/W/ Zr/W/ Zr/W/ Zr/W/ Zr/W/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Y/W Y/W/ Y/W/ Y/W/ Y/W/ Y/W/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Na/W Na/W/ Na/W/ Na/W/ Na/W/ Na/W/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Bi/W Bi/W/ Bi/W/ Bi/W/ Bi/W/ Bi/W/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Bi/Cs Bi/Cs/ Bi/Cs/ Bi/Cs/ Bi/Cs/ Bi/Cs/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Bi/Ca Bi/Ca/ Bi/Ca/ Bi/Ca/ Bi/Ca/ Bi/Ca/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/Pr Sr/Pr/ Sr/Pr/ Sr/Pr/ Sr/Pr/ Sr/Pr/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Bi/Sn Bi/Sn/ Bi/Sn/ Bi/Sn/ Bi/Sn/ Bi/Sn/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Bi/Sb Bi/Sb/ Bi/Sb/ Bi/Sb/ Bi/Sb/ Bi/Sb/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Ge/Hf Ge/Hf/ Ge/Hf/ Ge/Hf/ Ge/Hf/ Ge/Hf/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Hf/Sm Hf/Sm/ Hf/Sm/ Hf/Sm/ Hf/Sm/ Hf/Sm/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sb/Ag Sb/Ag/ Sb/Ag/ Sb/Ag/ Sb/Ag/ Sb/Ag/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sb/Bi Sb/Bi/ Sb/Bi/ Sb/Bi/ Sb/Bi/ Sb/Bi/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sb/Au Sb/Au/ Sb/Au/ Sb/Au/ Sb/Au/ Sb/Au/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sb/Sm Sb/Sm/ Sb/Sm/ Sb/Sm/ Sb/Sm/ Sb/Sm/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sb/Sr Sb/Sr/ Sb/Sr/ Sb/Sr/ Sb/Sr/ Sb/Sr/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sb/W Sb/W/ Sb/W/ Sb/W/ Sb/W/ Sb/W/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sb/Hf Sb/Hf/ Sb/Hf/ Sb/Hf/ Sb/Hf/ Sb/Hf/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sb/Yb Sb/Yb/ Sb/Yb/ Sb/Yb/ Sb/Yb/ Sb/Yb/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/Hf/K Sr/Hf/K/ Sr/Hf/K/ Sr/Hf/K/ Sr/Hf/K/ Sr/Hf/K/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sb/Sn Sb/Sn/ Sb/Sn/ Sb/Sn/ Sb/Sn/ Sb/Sn/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Yb/Au Yb/Au/ Yb/Au/ Yb/Au/ Yb/Au/ Yb/Au/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Yb/Ta Yb/Ta/ Yb/Ta/ Yb/Ta/ Yb/Ta/ Yb/Ta/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Yb/W Yb/W/ Yb/W/ Yb/W/ Yb/W/ Yb/W/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Yb/Sr Yb/Sr/ Yb/Sr/ Yb/Sr/ Yb/Sr/ Yb/Sr/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Yb/Pb Yb/Pb/ Yb/Pb/ Yb/Pb/ Yb/Pb/ Yb/Pb/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Yb/W Yb/W/ Yb/W/ Yb/W/ Yb/W/ Yb/W/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Yb/Ag Yb/Ag/ Yb/Ag/ Yb/Ag/ Yb/Ag/ Yb/Ag/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Au/Sr Au/Sr/ Au/Sr/ Au/Sr/ Au/Sr/ Au/Sr/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La W/Ge W/Ge/ W/Ge/ W/Ge/ W/Ge/ W/Ge/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/Hf/Rb Sr/Hf/Rb/ Sr/Hf/Rb/ Sr/Hf/Rb/ Sr/Hf/Rb/ Sr/Hf/Rb/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Ta/Sr Ta/Sr/ Ta/Sr/ Ta/Sr/ Ta/Sr/ Ta/Sr/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Ta/Hf Ta/Hf/ Ta/Hf/ Ta/Hf/ Ta/Hf/ Ta/Hf/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La W/Au W/Au/ W/Au/ W/Au/ W/Au/ W/Au/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Ca/W Ca/W/ Ca/W/ Ca/W/ Ca/W/ Ca/W/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Au/Re Au/Re/ Au/Re/ Au/Re/ Au/Re/ Au/Re/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sm/Li Sm/Li/ Sm/Li/ Sm/Li/ Sm/Li/ Sm/Li/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La La/K La/K/ La/K/ La/K/ La/K/ La/K/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Zn/Cs Zn/Cs/ Zn/Cs/ Zn/Cs/ Zn/Cs/ Zn/Cs/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Na/K/Mg Na/K/Mg/ Na/K/Mg/ Na/K/Mg/ Na/K/Mg/ Na/K/Mg/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Zr/Cs Zr/Cs/ Zr/Cs/ Zr/Cs/ Zr/Cs/ Zr/Cs/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Ca/Ce Ca/Ce/ Ca/Ce/ Ca/Ce/ Ca/Ce/ Ca/Ce/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/Zr/K Sr/Zr/K/ Sr/Zr/K/ Sr/Zr/K/ Sr/Zr/K/ Sr/Zr/K/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Na/Li/Cs Na/Li/Cs/ Na/Li/Cs/ Na/Li/Cs/ Na/Li/Cs/ Na/Li/Cs/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Li/Sr Li/Sr/ Li/Sr/ Li/Sr/ Li/Sr/ Li/Sr/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La La/Dy/K La/Dy/K/ La/Dy/K/ La/Dy/K/ La/Dy/K/ La/Dy/K/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Dy/K Dy/K/ Dy/K/ Dy/K/ Dy/K/ Dy/K/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La La/Mg La/Mg/ La/Mg/ La/Mg/ La/Mg/ La/Mg/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Na/Nd/In/K Na/Nd/In/K/ Na/Nd/In/K/ Na/Nd/In/K/ Na/Nd/In/K/ Na/Nd/In/K/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La In/Sr In/Sr/ In/Sr/ In/Sr/ In/Sr/ In/Sr/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/Cs Sr/Cs/ Sr/Cs/ Sr/Cs/ Sr/Cs/ Sr/Cs/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Rb/Ga/Tm/Cs Rb/Ga/Tm/Cs/ Rb/Ga/Tm/Cs/ Rb/Ga/Tm/Cs/ Rb/Ga/Tm/Cs/ Rb/Ga/Tm/Cs/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Ga/Cs Ga/Cs/ Ga/Cs/ Ga/Cs/ Ga/Cs/ Ga/Cs/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La K/La/Zr/Ag K/La/Zr/Ag/ K/La/Zr/Ag/ K/La/Zr/Ag/ K/La/Zr/Ag/ K/La/Zr/Ag/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/Zr Sr/Zr/ Sr/Zr/ Sr/Zr/ Sr/Zr/ Sr/Zr/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Lu/Fe Lu/Fe/ Lu/Fe/ Lu/Fe/ Lu/Fe/ Lu/Fe/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/Tm Sr/Tm/ Sr/Tm/ Sr/Tm/ Sr/Tm/ Sr/Tm/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La La/Dy La/Dy/ La/Dy/ La/Dy/ La/Dy/ La/Dy/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sm/Li/Sr Sm/Li/Sr/ Sm/Li/Sr/ Sm/Li/Sr/ Sm/Li/Sr/ Sm/Li/Sr/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Mg/K Mg/K/ Mg/K/ Mg/K/ Mg/K/ Mg/K/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Li/Rb/Ga Li/Rb/Ga/ Li/Rb/Ga/ Li/Rb/Ga/ Li/Rb/Ga/ Li/Rb/Ga/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Li/Cs/Tm Li/Cs/Tm/ Li/Cs/Tm/ Li/Cs/Tm/ Li/Cs/Tm/ Li/Cs/Tm/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Zr/K Zr/K/ Zr/K/ Zr/K/ Zr/K/ Zr/K/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Li/Cs Li/Cs/ Li/Cs/ Li/Cs/ Li/Cs/ Li/Cs/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/Ce Sr/Ce/ Sr/Ce/ Sr/Ce/ Sr/Ce/ Sr/Ce/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Li/K/La Li/K/La/ Li/K/La/ Li/K/La/ Li/K/La/ Li/K/La/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Ce/Zr/La Ce/Zr/La/ Ce/Zr/La/ Ce/Zr/La/ Ce/Zr/La/ Ce/Zr/La/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Ca/Al/La Ca/Al/La/ Ca/Al/La/ Ca/Al/La/ Ca/Al/La/ Ca/Al/La/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/Zn/La Sr/Zn/La/ Sr/Zn/La/ Sr/Zn/La/ Sr/Zn/La/ Sr/Zn/La/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/Cs/Zn Sr/Cs/Zn/ Sr/Cs/Zn/ Sr/Cs/Zn/ Sr/Cs/Zn/ Sr/Cs/Zn/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sm/Cs Sm/Cs/ Sm/Cs/ Sm/Cs/ Sm/Cs/ Sm/Cs/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La In/K In/K/ In/K/ In/K/ In/K/ In/K/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Ho/Cs/Li/La Ho/Cs/Li/La/ Ho/Cs/Li/La/ Ho/Cs/Li/La/ Ho/Cs/Li/La/ Ho/Cs/Li/La/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Cs/La/Na Cs/La/Na/ Cs/La/Na/ Cs/La/Na/ Cs/La/Na/ Cs/La/Na/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La La/S/Sr La/S/Sr/ La/S/Sr/ La/S/Sr/ La/S/Sr/ La/S/Sr/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La K/La/Zr/Ag K/La/Zr/Ag/ K/La/Zr/Ag/ K/La/Zr/Ag/ K/La/Zr/Ag/ K/La/Zr/Ag/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Lu/Tl Lu/Tl/ Lu/Tl/ Lu/Tl/ Lu/Tl/ Lu/Tl/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Pr/Zn Pr/Zn/ Pr/Zn/ Pr/Zn/ Pr/Zn/ Pr/Zn/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Rb/Sr/La Rb/Sr/La/ Rb/Sr/La/ Rb/Sr/La/ Rb/Sr/La/ Rb/Sr/La/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Na/Sr/Eu/Ca Na/Sr/Eu/Ca/ Na/Sr/Eu/Ca/ Na/Sr/Eu/Ca/ Na/Sr/Eu/Ca/ Na/Sr/Eu/Ca/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La K/Cs/Sr/La K/Cs/Sr/La/ K/Cs/Sr/La/ K/Cs/Sr/La/ K/Cs/Sr/La/ K/Cs/Sr/La/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Na/Sr/Lu Na/Sr/Lu/ Na/Sr/Lu/ Na/Sr/Lu/ Na/Sr/Lu/ Na/Sr/Lu/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/Eu/Dy Sr/Eu/Dy/ Sr/Eu/Dy/ Sr/Eu/Dy/ Sr/Eu/Dy/ Sr/Eu/Dy/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Lu/Nb Lu/Nb/ Lu/Nb/ Lu/Nb/ Lu/Nb/ Lu/Nb/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/Tb Sr/Tb/ Sr/Tb/ Sr/Tb/ Sr/Tb/ Sr/Tb/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La La/Dy/Gd La/Dy/Gd/ La/Dy/Gd/ La/Dy/Gd/ La/Dy/Gd/ La/Dy/Gd/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Na/Mg/Tl/P Na/Mg/Tl/P/ Na/Mg/Tl/P/ Na/Mg/Tl/P/ Na/Mg/Tl/P/ Na/Mg/Tl/P/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Na/Pt Na/Pt/ Na/Pt/ Na/Pt/ Na/Pt/ Na/Pt/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Gd/Li/K Gd/Li/K/ Gd/Li/K/ Gd/Li/K/ Gd/Li/K/ Gd/Li/K/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Rb/K/Lu Rb/K/Lu/ Rb/K/Lu/ Rb/K/Lu/ Rb/K/Lu/ Rb/K/Lu/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/La/Dy/S Sr/La/Dy/S/ Sr/La/Dy/S/ Sr/La/Dy/S/ Sr/La/Dy/S/ Sr/La/Dy/S/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Na/Ce/Co Na/Ce/Co/ Na/Ce/Co/ Na/Ce/Co/ Na/Ce/Co/ Na/Ce/Co/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Na/Ce Na/Ce/ Na/Ce/ Na/Ce/ Na/Ce/ Na/Ce/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Na/Ga/Gd/Al Na/Ga/Gd/Al/ Na/Ga/Gd/Al/ Na/Ga/Gd/Al/ Na/Ga/Gd/Al/ Na/Ga/Gd/Al/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Ba/Rh/Ta Ba/Rh/Ta/ Ba/Rh/Ta/ Ba/Rh/Ta/ Ba/Rh/Ta/ Ba/Rh/Ta/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Ba/Ta Ba/Ta/ Ba/Ta/ Ba/Ta/ Ba/Ta/ Ba/Ta/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Na/Al/Bi Na/Al/Bi/ Na/Al/Bi/ Na/Al/Bi/ Na/Al/Bi/ Na/Al/Bi/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Cs/Eu/S Cs/Eu/S/ Cs/Eu/S/ Cs/Eu/S/ Cs/Eu/S/ Cs/Eu/S/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sm/Tm/Yb/Fe Sm/Tm/Yb/Fe/ Sm/Tm/Yb/Fe/ Sm/Tm/Yb/Fe/ Sm/Tm/Yb/Fe/ Sm/Tm/Yb/Fe/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sm/Tm/Yb Sm/Tm/Yb/ Sm/Tm/Yb/ Sm/Tm/Yb/ Sm/Tm/Yb/ Sm/Tm/Yb/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Hf/Zr/Ta Hf/Zr/Ta/ Hf/Zr/Ta/ Hf/Zr/Ta/ Hf/Zr/Ta/ Hf/Zr/Ta/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Rb/Gd/Li/K Rb/Gd/Li/K/ Rb/Gd/Li/K/ Rb/Gd/Li/K/ Rb/Gd/Li/K/ Rb/Gd/Li/K/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—Lai/K Ce—La Gd/Ho/Al/P Gd/Ho/Al/P/ Gd/Ho/Al/P/ Gd/Ho/Al/P/ Gd/Ho/Al/P/ Gd/Ho/Al/P/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Na/Ca/Lu Na/Ca/Lu/ Na/Ca/Lu/ Na/Ca/Lu/ Na/Ca/Lu/ Na/Ca/Lu/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Cu/Sn Cu/Sn/ Cu/Sn/ Cu/Sn/ Cu/Sn/ Cu/Sn/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Ag/Au Ag/Au/ Ag/Au/ Ag/Au/ Ag/Au/ Ag/Au/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Al/Bi Al/Bi/ Al/Bi/ Al/Bi/ Al/Bi/ Al/Bi/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Al/Mo Al/Mo/ Al/Mo/ Al/Mo/ Al/Mo/ Al/Mo/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Al/Nb Al/Nb/ Al/Nb/ Al/Nb/ Al/Nb/ Al/Nb/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/Ce/K Sr/Ce/K/ Sr/Ce/K/ Sr/Ce/K/ Sr/Ce/K/ Sr/Ce/K/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Au/Pt Au/Pt/ Au/Pt/ Au/Pt/ Au/Pt/ Au/Pt/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Ga/Bi Ga/Bi/ Ga/Bi/ Ga/Bi/ Ga/Bi/ Ga/Bi/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Mg/W Mg/W/ Mg/W/ Mg/W/ Mg/W/ Mg/W/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Pb/Au Pb/Au/ Pb/Au/ Pb/Au/ Pb/Au/ Pb/Au/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sn/Mg Sn/Mg/ Sn/Mg/ Sn/Mg/ Sn/Mg/ Sn/Mg/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Zn/Bi Zn/Bi/ Zn/Bi/ Zn/Bi/ Zn/Bi/ Zn/Bi/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/Ta Sr/Ta/ Sr/Ta/ Sr/Ta/ Sr/Ta/ Sr/Ta/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Na Na/ Na/ Na/ Na/ Na/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr Sr/ Sr/ Sr/ Sr/ Sr/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Ca Ca/ Ca/ Ca/ Ca/ Ca/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Yb Yb/ Yb/ Yb/ Yb/ Yb/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Cs Cs/ Cs/ Cs/ Cs/ Cs/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sb Sb/ Sb/ Sb/ Sb/ Sb/ La_(3.8)Nd_(0.2)O₆/ Y—La/ Zr—La/ Pr—La/ Ce—La/ Zn/Bi Zn/Bi Zn/Bi Zn/Bi Zn/Bi Gd/Ho Gd/Ho/ Gd/Ho/ Gd/Ho/ Gd/Ho/ Gd/Ho/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Zr/Bi Zr/Bi/ Zr/Bi/ Zr/Bi/ Zr/Bi/ Zr/Bi/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Ho/Sr Ho/Sr/ Ho/Sr/ Ho/Sr/ Ho/Sr/ Ho/Sr/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Gd/Ho/Sr Gd/Ho/Sr/ Gd/Ho/Sr/ Gd/Ho/Sr/ Gd/Ho/Sr/ Gd/Ho/Sr/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Ca/Sr Ca/Sr/ Ca/Sr/ Ca/Sr/ Ca/Sr/ Ca/Sr/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Ca/Sr/W Ca/Sr/W/ Ca/Sr/W/ Ca/Sr/W/ Ca/Sr/W/ Ca/Sr/W/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Na/Zr/Eu/Tm Na/Zr/Eu/Tm/ Na/Zr/Eu/Tm/ Na/Zr/Eu/Tm/ Na/Zr/Eu/Tm/ Na/Zr/Eu/Tm/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/Ho/Tm/Na Sr/Ho/Tm/Na/ Sr/Ho/Tm/Na/ Sr/Ho/Tm/Na/ Sr/Ho/Tm/Na/ Sr/Ho/Tm/Na/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/Pb Sr/Pb/ Sr/Pb/ Sr/Pb/ Sr/Pb/ Sr/Pb/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/W/Li Sr/W/Li/ Sr/W/Li/ Sr/W/Li/ Sr/W/Li/ Sr/W/Li/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Ca/Sr/W Ca/Sr/W/ Ca/Sr/W/ Ca/Sr/W/ Ca/Sr/W/ Ca/Sr/W/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/Hf Sr/Hf/ Sr/Hf/ Sr/Hf/ Sr/Hf/ Sr/Hf/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Au/Re Au/Re/ Au/Re/ Au/Re/ Au/Re/ Au/Re/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/W Sr/W/ Sr/W/ Sr/W/ Sr/W/ Sr/W/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La La/Nd La/Nd/ La/Nd/ La/Nd/ La/Nd/ La/Nd/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La La/Sm La/Sm/ La/Sm/ La/Sm/ La/Sm/ La/Sm/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La La/Ce La/Ce/ La/Ce/ La/Ce/ La/Ce/ La/Ce/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La La/Sr La/Sr/ La/Sr/ La/Sr/ La/Sr/ La/Sr/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La La/Nd/Sr La/Nd/Sr/ La/Nd/Sr/ La/Nd/Sr/ La/Nd/Sr/ La/Nd/Sr/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La La/Bi/Sr La/Bi/Sr/ La/Bi/Sr/ La/Bi/Sr/ La/Bi/Sr/ La/Bi/Sr/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La La/Ce/Nd/Sr La/Ce/Nd/Sr/ La/Ce/Nd/Sr/ La/Ce/Nd/Sr/ La/Ce/Nd/Sr/ La/Ce/Nd/Sr/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La La/Bi/Ce/Nd/Sr La/Bi/Ce/Nd/Sr/ La/Bi/Ce/Nd/Sr/ La/Bi/Ce/Nd/Sr/ La/Bi/Ce/Nd/Sr/ La/Bi/Ce/Nd/Sr/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Eu/Gd Eu/Gd/ Eu/Gd/ Eu/Gd/ Eu/Gd/ Eu/Gd/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Ca/Na Ca/Na/ Ca/Na/ Ca/Na/ Ca/Na/ Ca/Na/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Eu/Sm Eu/Sm/ Eu/Sm/ Eu/Sm/ Eu/Sm/ Eu/Sm/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Eu/Sr Eu/Sr/ Eu/Sr/ Eu/Sr/ Eu/Sr/ Eu/Sr/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Mg/Sr Mg/Sr/ Mg/Sr/ Mg/Sr/ Mg/Sr/ Mg/Sr/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Ce/Mg Ce/Mg/ Ce/Mg/ Ce/Mg/ Ce/Mg/ Ce/Mg/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Gd/Sm Gd/Sm/ Gd/Sm/ Gd/Sm/ Gd/Sm/ Gd/Sm/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Au/Pb Au/Pb/ Au/Pb/ Au/Pb/ Au/Pb/ Au/Pb/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Bi/Hf Bi/Hf/ Bi/Hf/ Bi/Hf/ Bi/Hf/ Bi/Hf/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Rb/S Rb/S/ Rb/S/ Rb/S/ Rb/S/ Rb/S/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Sr/Nd Sr/Nd/ Sr/Nd/ Sr/Nd/ Sr/Nd/ Sr/Nd/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Eu/Y Eu/Y/ Eu/Y/ Eu/Y/ Eu/Y/ Eu/Y/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Mg/Nd Mg/Nd/ Mg/Nd/ Mg/Nd/ Mg/Nd/ Mg/Nd/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La La/Mg La/Mg/ La/Mg/ La/Mg/ La/Mg/ La/Mg/ La_(3.8)Nd_(0.2)O₆ NY—La Zr—La Pr—La Ce—La Mg/Nd/Fe Mg/Nd/Fe/ Mg/Nd/Fe/ Mg/Nd/Fe/ Mg/Nd/Fe/ Mg/Nd/Fe/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La Rb/Sr Rb/Sr/ Rb/Sr/ Rb/Sr/ Rb/Sr/ Rb/Sr/ La_(3.8)Nd_(0.2)O₆ Y—La Zr—La Pr—La Ce—La

TABLE 12 NANOWIRES (NW) DOPED WITH SPECIFIC DOPANTS (DOP) NW Dop Ln1_(4−x)Ln2_(x)O₆* La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Eu/Na Eu/Na/ Eu/Na/ Eu/Na/ Eu/Na/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/Na Sr/Na/ Sr/Na/ Sr/Na/ Sr/Na/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Na/Zr/Eu/Ca Na/Zr/Eu/Ca/ Na/Zr/Eu/Ca/ Na/Zr/Eu/Ca/ Na/Zr/Eu/Ca/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Mg/Na Mg/Na/ Mg/Na/ Mg/Na/ Mg/Na/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/Sm/Ho/Tm Sr/Sm/Ho/Tm/ Sr/Sm/Ho/Tm/ Sr/Sm/Ho/Tm/ Sr/Sm/Ho/Tm/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/W Sr/W/ Sr/W/ Sr/W/ Sr/W/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Mg/La/K Mg/La/K/ Mg/La/K/ Mg/La/K/ Mg/La/K/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Na/K/Mg/Tm Na/K/Mg/Tm/ Na/K/Mg/Tm/ Na/K/Mg/Tm/ Na/K/Mg/Tm/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Na/Dy/K Na/Dy/K/ Na/Dy/K/ Na/Dy/K/ Na/Dy/K/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Na/La/Dy Na/La/Dy/ Na/La/Dy/ Na/La/Dy/ Na/La/Dy/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Na/La/Eu Na/La/Eu/ Na/La/Eu/ Na/La/Eu/ Na/La/Eu/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Na/La/Eu/In Na/La/Eu/In/ Na/La/Eu/In/ Na/La/Eu/In/ Na/La/Eu/In/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Na/La/K Na/La/K/ Na/La/K/ Na/La/K/ Na/La/K/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Na/La/Li/Cs Na/La/Li/Cs/ Na/La/Li/Cs/ Na/La/Li/Cs/ Na/La/Li/Cs/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO K/La K/La/ K/La/ K/La/ K/La/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO K/La/S K/La/S/ K/La/S/ K/La/S/ K/La/S/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO K/Na K/Na/ K/Na/ K/Na/ K/Na/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Li/Cs Li/Cs/ Li/Cs/ Li/Cs/ Li/Cs/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Li/Cs/La Li/Cs/La/ Li/Cs/La/ Li/Cs/La/ Li/Cs/La/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Li/Cs/La/Tm Li/Cs/La/Tm/ Li/Cs/La/Tm/ Li/Cs/La/Tm/ Li/Cs/La/Tm/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Li/Cs/Sr/Tm Li/Cs/Sr/Tm/ Li/Cs/Sr/Tm/ Li/Cs/Sr/Tm/ Li/Cs/Sr/Tm/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Li/Sr/Cs Li/Sr/Cs/ Li/Sr/Cs/ Li/Sr/Cs/ Li/Sr/Cs/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Li/Sr/Zn/K Li/Sr/Zn/K/ Li/Sr/Zn/K/ Li/Sr/Zn/K/ Li/Sr/Zn/K/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Li/Ga/Cs Li/Ga/Cs/ Li/Ga/Cs/ Li/Ga/Cs/ Li/Ga/Cs/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Li/K/Sr/La Li/K/Sr/La/ Li/K/Sr/La/ Li/K/Sr/La/ Li/K/Sr/La/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Li/Na Li/Na/ Li/Na/ Li/Na/ Li/Na/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Li/Na/Rb/Ga Li/Na/Rb/Ga/ Li/Na/Rb/Ga/ Li/Na/Rb/Ga/ Li/Na/Rb/Ga/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/Zr Sr/Zr/ Sr/Zr/ Sr/Zr/ Sr/Zr/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Li/Na/Sr Li/Na/Sr/ Li/Na/Sr/ Li/Na/Sr/ Li/Na/Sr/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Li/Na/Sr/La Li/Na/Sr/La/ Li/Na/Sr/La/ Li/Na/Sr/La/ Li/Na/Sr/La/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Li/Sm/Cs Li/Sm/Cs/ Li/Sm/Cs/ Li/Sm/Cs/ Li/Sm/Cs/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Ba/Sm/Yb/S Ba/Sm/Yb/S/ Ba/Sm/Yb/S/ Ba/Sm/Yb/S/ Ba/Sm/Yb/S/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Ba/Tm/K/La Ba/Tm/K/La/ Ba/Tm/K/La/ Ba/Tm/K/La/ Ba/Tm/K/La/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Ba/Tm/Zn/K Ba/Tm/Zn/K/ Ba/Tm/Zn/K/ Ba/Tm/Zn/K/ Ba/Tm/Zn/K/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Cs/K/La Cs/K/La/ Cs/K/La/ Cs/K/La/ Cs/K/La/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Cs/La/Tm/Na Cs/La/Tm/Na/ Cs/La/Tm/Na/ Cs/La/Tm/Na/ Cs/La/Tm/Na/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Cs/Li/K/La Cs/Li/K/La/ Cs/Li/K/La/ Cs/Li/K/La/ Cs/Li/K/La/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sm/Li/Sr/Cs Sm/Li/Sr/Cs/ Sm/Li/Sr/Cs/ Sm/Li/Sr/Cs/ Sm/Li/Sr/Cs/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/Cs/La Sr/Cs/La/ Sr/Cs/La/ Sr/Cs/La/ Sr/Cs/La/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/Tm/Li/Cs Sr/Tm/Li/Cs/ Sr/Tm/Li/Cs/ Sr/Tm/Li/Cs/ Sr/Tm/Li/Cs/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Zn/K Zn/K/ Zn/K/ Zn/K/ Zn/K/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Zr/Cs/K/La Zr/Cs/K/La/ Zr/Cs/K/La/ Zr/Cs/K/La/ Zr/Cs/K/La/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Rb/Ca/In/Ni Rb/Ca/In/Ni/ Rb/Ca/In/Ni/ Rb/Ca/In/Ni/ Rb/Ca/In/Ni/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/Ho/Tm Sr/Ho/Tm/ Sr/Ho/Tm/ Sr/Ho/Tm/ Sr/Ho/Tm/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO La/Nd/S La/Nd/S/ La/Nd/S/ La/Nd/S/ La/Nd/S/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/Tb Sr/Tb/ Sr/Tb/ Sr/Tb/ Sr/Tb/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Li/Rb/Ca Li/Rb/Ca/ Li/Rb/Ca/ Li/Rb/Ca/ Li/Rb/Ca/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Li/K Li/K/ Li/K/ Li/K/ Li/K/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Tm/Lu/Ta/P Tm/Lu/Ta/P/ Tm/Lu/Ta/P/ Tm/Lu/Ta/P/ Tm/Lu/Ta/P/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Rb/Ca/Dy/P Rb/Ca/Dy/P/ Rb/Ca/Dy/P/ Rb/Ca/Dy/P/ Rb/Ca/Dy/P/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Mg/La/Yb/Zn Mg/La/Yb/Zn/ Mg/La/Yb/Zn/ Mg/La/Yb/Zn/ Mg/La/Yb/Zn/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Rb/Sr/Lu Rb/Sr/Lu/ Rb/Sr/Lu/ Rb/Sr/Lu/ Rb/Sr/Lu/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Na/Sr/Lu/Nb Na/Sr/Lu/Nb/ Na/Sr/Lu/Nb/ Na/Sr/Lu/Nb/ Na/Sr/Lu/Nb/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Na/Eu/Hf Na/Eu/Hf/ Na/Eu/Hf/ Na/Eu/Hf/ Na/Eu/Hf/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Dy/Rb/Gd Dy/Rb/Gd/ Dy/Rb/Gd/ Dy/Rb/Gd/ Dy/Rb/Gd/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Na/Pt/Bi Na/Pt/Bi/ Na/Pt/Bi/ Na/Pt/Bi/ Na/Pt/Bi/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Rb/Hf Rb/Hf/ Rb/Hf/ Rb/Hf/ Rb/Hf/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Ca/Cs Ca/Cs/ Ca/Cs/ Ca/Cs/ Ca/Cs/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Ca/Mg/Na Ca/Mg/Na/ Ca/Mg/Na/ Ca/Mg/Na/ Ca/Mg/Na/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Hf/Bi Hf/Bi/ Hf/Bi/ Hf/Bi/ Hf/Bi/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/Sn Sr/Sn/ Sr/Sn/ Sr/Sn/ Sr/Sn/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/W Sr/W/ Sr/W/ Sr/W/ Sr/W/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/Nb Sr/Nb/ Sr/Nb/ Sr/Nb/ Sr/Nb/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Zr/W Zr/W/ Zr/W/ Zr/W/ Zr/W/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Y/W Y/W/ Y/W/ Y/W/ Y/W/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Na/W Na/W/ Na/W/ Na/W/ Na/W/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/Ce Sr/Ce/ Sr/Ce/ Sr/Ce/ Sr/Ce/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Bi/W Bi/W/ Bi/W/ Bi/W/ Bi/W/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Bi/Cs Bi/Cs/ Bi/Cs/ Bi/Cs/ Bi/Cs/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Bi/Ca Bi/Ca/ Bi/Ca/ Bi/Ca/ Bi/Ca/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Bi/Sn Bi/Sn/ Bi/Sn/ Bi/Sn/ Bi/Sn/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Bi/Sb Bi/Sb/ Bi/Sb/ Bi/Sb/ Bi/Sb/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Ge/Hf Ge/Hf/ Ge/Hf/ Ge/Hf/ Ge/Hf/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Hf/Sm Hf/Sm/ Hf/Sm/ Hf/Sm/ Hf/Sm/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sb/Ag Sb/Ag/ Sb/Ag/ Sb/Ag/ Sb/Ag/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sb/Bi Sb/Bi/ Sb/Bi/ Sb/Bi/ Sb/Bi/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sb/Au Sb/Au/ Sb/Au/ Sb/Au/ Sb/Au/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sb/Sm Sb/Sm/ Sb/Sm/ Sb/Sm/ Sb/Sm/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sb/Sr Sb/Sr/ Sb/Sr/ Sb/Sr/ Sb/Sr/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sb/W Sb/W/ Sb/W/ Sb/W/ Sb/W/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sb/Hf Sb/Hf/ Sb/Hf/ Sb/Hf/ Sb/Hf/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sb/Yb Sb/Yb/ Sb/Yb/ Sb/Yb/ Sb/Yb/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/Pr/K Sr/Pr/K/ Sr/Pr/K/ Sr/Pr/K/ Sr/Pr/K/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sb/Sn Sb/Sn/ Sb/Sn/ Sb/Sn/ Sb/Sn/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Yb/Au Yb/Au/ Yb/Au/ Yb/Au/ Yb/Au/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Yb/Ta Yb/Ta/ Yb/Ta/ Yb/Ta/ Yb/Ta/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Yb/W Yb/W/ Yb/W/ Yb/W/ Yb/W/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Yb/Sr Yb/Sr/ Yb/Sr/ Yb/Sr/ Yb/Sr/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Yb/Pb Yb/Pb/ Yb/Pb/ Yb/Pb/ Yb/Pb/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Yb/W Yb/W/ Yb/W/ Yb/W/ Yb/W/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Yb/Ag Yb/Ag/ Yb/Ag/ Yb/Ag/ Yb/Ag/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Au/Sr Au/Sr/ Au/Sr/ Au/Sr/ Au/Sr/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO W/Ge W/Ge/ W/Ge/ W/Ge/ W/Ge/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Ta/Sr Ta/Sr/ Ta/Sr/ Ta/Sr/ Ta/Sr/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Ta/Hf Ta/Hf/ Ta/Hf/ Ta/Hf/ Ta/Hf/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO W/Au W/Au/ W/Au/ W/Au/ W/Au/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Ca/W Ca/W/ Ca/W/ Ca/W/ Ca/W/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Au/Re Au/Re/ Au/Re/ Au/Re/ Au/Re/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sm/Li Sm/Li/ Sm/Li/ Sm/Li/ Sm/Li/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO La/K La/K/ La/K/ La/K/ La/K/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Zn/Cs Zn/Cs/ Zn/Cs/ Zn/Cs/ Zn/Cs/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/Zr/K Sr/Zr/K/ Sr/Zr/K/ Sr/Zr/K/ Sr/Zr/K/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Na/K/Mg Na/K/Mg/ Na/K/Mg/ Na/K/Mg/ Na/K/Mg/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Zr/Cs Zr/Cs/ Zr/Cs/ Zr/Cs/ Zr/Cs/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Ca/Ce Ca/Ce/ Ca/Ce/ Ca/Ce/ Ca/Ce/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Na/Li/Cs Na/Li/Cs/ Na/Li/Cs/ Na/Li/Cs/ Na/Li/Cs/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Li/Sr Li/Sr/ Li/Sr/ Li/Sr/ Li/Sr/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO La/Dy/K La/Dy/K/ La/Dy/K/ La/Dy/K/ La/Dy/K/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Dy/K Dy/K/ Dy/K/ Dy/K/ Dy/K/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO La/Mg La/Mg/ La/Mg/ La/Mg/ La/Mg/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Na/Nd/In/K Na/Nd/In/K/ Na/Nd/In/K/ Na/Nd/In/K/ Na/Nd/In/K/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO In/Sr In/Sr/ In/Sr/ In/Sr/ In/Sr/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/Cs Sr/Cs/ Sr/Cs/ Sr/Cs/ Sr/Cs/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Rb/Ga/Tm/Cs Rb/Ga/Tm/Cs/ Rb/Ga/Tm/Cs/ Rb/Ga/Tm/Cs/ Rb/Ga/Tm/Cs/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Ga/Cs Ga/Cs/ Ga/Cs/ Ga/Cs/ Ga/Cs/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO K/La/Zr/Ag K/La/Zr/Ag/ K/La/Zr/Ag/ K/La/Zr/Ag/ K/La/Zr/Ag/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Lu/Fe Lu/Fe/ Lu/Fe/ Lu/Fe/ Lu/Fe/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/Tm Sr/Tm/ Sr/Tm/ Sr/Tm/ Sr/Tm/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO La/Dy La/Dy/ La/Dy/ La/Dy/ La/Dy/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sm/Li/Sr Sm/Li/Sr/ Sm/Li/Sr/ Sm/Li/Sr/ Sm/Li/Sr/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Mg/K Mg/K/ Mg/K/ Mg/K/ Mg/K/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Li/Rb/Ga Li/Rb/Ga/ Li/Rb/Ga/ Li/Rb/Ga/ Li/Rb/Ga/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/Ce/K Sr/Ce/K/ Sr/Ce/K/ Sr/Ce/K/ Sr/Ce/K/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Li/Cs/Tm Li/Cs/Tm/ Li/Cs/Tm/ Li/Cs/Tm/ Li/Cs/Tm/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Zr/K Zr/K/ Zr/K/ Zr/K/ Zr/K/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Li/Cs Li/Cs/ Li/Cs/ Li/Cs/ Li/Cs/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Li/K/La Li/K/La/ Li/K/La/ Li/K/La/ Li/K/La/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Ce/Zr/La Ce/Zr/La/ Ce/Zr/La/ Ce/Zr/La/ Ce/Zr/La/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Ca/Al/La Ca/Al/La/ Ca/Al/La/ Ca/Al/La/ Ca/Al/La/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/Zn/La Sr/Zn/La/ Sr/Zn/La/ Sr/Zn/La/ Sr/Zn/La/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/Cs/Zn Sr/Cs/Zn/ Sr/Cs/Zn/ Sr/Cs/Zn/ Sr/Cs/Zn/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sm/Cs Sm/Cs/ Sm/Cs/ Sm/Cs/ Sm/Cs/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO In/K In/K/ In/K/ In/K/ In/K/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/Pr Sr/Pr/ Sr/Pr/ Sr/Pr/ Sr/Pr/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Ho/Cs/Li/La Ho/Cs/Li/La/ Ho/Cs/Li/La/ Ho/Cs/Li/La/ Ho/Cs/Li/La/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Cs/La/Na Cs/La/Na/ Cs/La/Na/ Cs/La/Na/ Cs/La/Na/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO La/S/Sr La/S/Sr/ La/S/Sr/ La/S/Sr/ La/S/Sr/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO K/La/Zr/Ag K/La/Zr/Ag/ K/La/Zr/Ag/ K/La/Zr/Ag/ K/La/Zr/Ag/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Lu/Tl Lu/Tl/ Lu/Tl/ Lu/Tl/ Lu/Tl/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Pr/Zn Pr/Zn/ Pr/Zn/ Pr/Zn/ Pr/Zn/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Rb/Sr/La Rb/Sr/La/ Rb/Sr/La/ Rb/Sr/La/ Rb/Sr/La/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Na/Sr/Eu/Ca Na/Sr/Eu/Ca/ Na/Sr/Eu/Ca/ Na/Sr/Eu/Ca/ Na/Sr/Eu/Ca/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO K/Cs/Sr/La K/Cs/Sr/La/ K/Cs/Sr/La/ K/Cs/Sr/La/ K/Cs/Sr/La/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Na/Sr/Lu Na/Sr/Lu/ Na/Sr/Lu/ Na/Sr/Lu/ Na/Sr/Lu/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/Eu/Dy Sr/Eu/Dy/ Sr/Eu/Dy/ Sr/Eu/Dy/ Sr/Eu/Dy/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Lu/Nb Lu/Nb/ Lu/Nb/ Lu/Nb/ Lu/Nb/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO La/Dy/Gd La/Dy/Gd/ La/Dy/Gd/ La/Dy/Gd/ La/Dy/Gd/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Na/Mg/Tl/P Na/Mg/Tl/P/ Na/Mg/Tl/P/ Na/Mg/Tl/P/ Na/Mg/Tl/P/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Na/Pt Na/Pt/ Na/Pt/ Na/Pt/ Na/Pt/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Gd/Li/K Gd/Li/K/ Gd/Li/K/ Gd/Li/K/ Gd/Li/K/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Rb/K/Lu Rb/K/Lu/ Rb/K/Lu/ Rb/K/Lu/ Rb/K/Lu/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/La/Dy/S Sr/La/Dy/S/ Sr/La/Dy/S/ Sr/La/Dy/S/ Sr/La/Dy/S/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Na/Ce/Co Na/Ce/Co/ Na/Ce/Co/ Na/Ce/Co/ Na/Ce/Co/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Na/Ce Na/Ce/ Na/Ce/ Na/Ce/ Na/Ce/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/Tb/K Sr/Tb/K/ Sr/Tb/K/ Sr/Tb/K/ Sr/Tb/K/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Na/Ga/Gd/Al Na/Ga/Gd/Al/ Na/Ga/Gd/Al/ Na/Ga/Gd/Al/ Na/Ga/Gd/Al/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Ba/Rh/Ta Ba/Rh/Ta/ Ba/Rh/Ta/ Ba/Rh/Ta/ Ba/Rh/Ta/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Ba/Ta Ba/Ta/ Ba/Ta/ Ba/Ta/ Ba/Ta/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Na/Al/Bi Na/Al/Bi/ Na/Al/Bi/ Na/Al/Bi/ Na/Al/Bi/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Cs/Eu/S Cs/Eu/S/ Cs/Eu/S/ Cs/Eu/S/ Cs/Eu/S/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sm/Tm/Yb/Fe Sm/Tm/Yb/Fe/ Sm/Tm/Yb/Fe/ Sm/Tm/Yb/Fe/ Sm/Tm/Yb/Fe/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sm/Tm/Yb Sm/Tm/Yb/ Sm/Tm/Yb/ Sm/Tm/Yb/ Sm/Tm/Yb/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Hf/Zr/Ta Hf/Zr/Ta/ Hf/Zr/Ta/ Hf/Zr/Ta/ Hf/Zr/Ta/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Rb/Gd/Li/K Rb/Gd/Li/K/ Rb/Gd/Li/K/ Rb/Gd/Li/K/ Rb/Gd/Li/K/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Gd/Ho/Al/P Gd/Ho/Al/P/ Gd/Ho/Al/P/ Gd/Ho/Al/P/ Gd/Ho/Al/P/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Na/Ca/Lu Na/Ca/Lu/ Na/Ca/Lu/ Na/Ca/Lu/ Na/Ca/Lu/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Cu/Sn Cu/Sn/ Cu/Sn/ Cu/Sn/ Cu/Sn/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Ag/Au Ag/Au/ Ag/Au/ Ag/Au/ Ag/Au/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Al/Bi Al/Bi/ Al/Bi/ Al/Bi/ Al/Bi/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Al/Mo Al/Mo/ Al/Mo/ Al/Mo/ Al/Mo/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/Hf/Rb Sr/Hf/Rb/ Sr/Hf/Rb/ Sr/Hf/Rb/ Sr/Hf/Rb/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Al/Nb Al/Nb/ Al/Nb/ Al/Nb/ Al/Nb/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Au/Pt Au/Pt/ Au/Pt/ Au/Pt/ Au/Pt/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Ga/Bi Ga/Bi/ Ga/Bi/ Ga/Bi/ Ga/Bi/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Mg/W Mg/W/ Mg/W/ Mg/W/ Mg/W/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Pb/Au Pb/Au/ Pb/Au/ Pb/Au/ Pb/Au/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sn/Mg Sn/Mg/ Sn/Mg/ Sn/Mg/ Sn/Mg/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Zn/Bi Zn/Bi/ Zn/Bi/ Zn/Bi/ Zn/Bi/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/Ta Sr/Ta/ Sr/Ta/ Sr/Ta/ Sr/Ta/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Na Na/ Na/ Na/ Na/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr Sr/ Sr/ Sr/ Sr/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Ca Ca/ Ca/ Ca/ Ca/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Yb Yb/ Yb/ Yb/ Yb/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Cs Cs/ Cs/ Cs/ Cs/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sb Sb/ Sb/ Sb/ Sb/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Gd/Ho Gd/Ho/ Gd/Ho/ Gd/Ho/ Gd/Ho/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Zr/Bi Zr/Bi/ Zr/Bi/ Zr/Bi/ Zr/Bi/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Ho/Sr Ho/Sr/ Ho/Sr/ Ho/Sr/ Ho/Sr/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/B Sr/B/ Sr/B/ Sr/B/ Sr/B/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Gd/Ho/Sr Gd/Ho/Sr/ Gd/Ho/Sr/ Gd/Ho/Sr/ Gd/Ho/Sr/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Ca/Sr Ca/Sr/ Ca/Sr/ Ca/Sr/ Ca/Sr/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Ca/Sr/W Ca/Sr/W/ Ca/Sr/W/ Ca/Sr/W/ Ca/Sr/W/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Na/Zr/Eu/Tm Na/Zr/Eu/Tm/ Na/Zr/Eu/Tm/ Na/Zr/Eu/Tm/ Na/Zr/Eu/Tm/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/Ho/Tm/Na Sr/Ho/Tm/Na/ Sr/Ho/Tm/Na/ Sr/Ho/Tm/Na/ Sr/Ho/Tm/Na/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/Pb Sr/Pb/ Sr/Pb/ Sr/Pb/ Sr/Pb/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/W/Li Sr/W/Li/ Sr/W/Li/ Sr/W/Li/ Sr/W/Li/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Ca/Sr/W Ca/Sr/W/ Ca/Sr/W/ Ca/Sr/W/ Ca/Sr/W/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/Hf Sr/Hf/ Sr/Hf/ Sr/Hf/ Sr/Hf/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Au/Re Au/Re/ Au/Re/ Au/Re/ Au/Re/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/W Sr/W/ Sr/W/ Sr/W/ Sr/W/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO La/Nd La/Nd/ La/Nd/ La/Nd/ La/Nd/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO La/Sm La/Sm/ La/Sm/ La/Sm/ La/Sm/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO La/Ce La/Ce/ La/Ce/ La/Ce/ La/Ce/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO La/Sr La/Sr/ La/Sr/ La/Sr/ La/Sr/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO La/Nd/Sr La/Nd/Sr/ La/Nd/Sr/ La/Nd/Sr/ La/Nd/Sr/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO La/Bi/Sr La/Bi/Sr/ La/Bi/Sr/ La/Bi/Sr/ La/Bi/Sr/ L Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO La/Ce/Nd/Sr La/Ce/Nd/Sr/ La/Ce/Nd/Sr/ La/Ce/Nd/Sr/ La/Ce/Nd/Sr/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO La/Bi/Ce/Nd/Sr La/Bi/Ce/Nd/Sr/ La/Bi/Ce/Nd/Sr/ La/Bi/Ce/Nd/Sr/ La/Bi/Ce/Nd/Sr/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Eu/Gd Eu/Gd/ Eu/Gd/ Eu/Gd/ Eu/Gd/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Ca/Na Ca/Na/ Ca/Na/ Ca/Na/ Ca/Na/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Eu/Sm Eu/Sm/ Eu/Sm/ Eu/Sm/ Eu/Sm/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Eu/Sr Eu/Sr/ Eu/Sr/ Eu/Sr/ Eu/Sr/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Mg/Sr Mg/Sr/ Mg/Sr/ Mg/Sr/ Mg/Sr/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Ce/Mg Ce/Mg/ Ce/Mg/ Ce/Mg/ Ce/Mg/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Gd/Sm Gd/Sm/ Gd/Sm/ Gd/Sm/ Gd/Sm/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Au/Pb Au/Pb/ Au/Pb/ Au/Pb/ Au/Pb/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Bi/Hf Bi/Hf/ Bi/Hf/ Bi/Hf/ Bi/Hf/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Rb/S Rb/S/ Rb/S/ Rb/S/ Rb/S/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/Nd Sr/Nd/ Sr/Nd/ Sr/Nd/ Sr/Nd/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Eu/Y Eu/Y/ Eu/Y/ Eu/Y/ Eu/Y/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Sr/Hf/K Sr/Hf/K/ Sr/Hf/K/ Sr/Hf/K/ Sr/Hf/K/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Mg/Nd Mg/Nd/ Mg/Nd/ Mg/Nd/ Mg/Nd/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO La/Mg La/Mg/ La/Mg/ La/Mg/ La/Mg/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Mg/Nd/Fe Mg/Nd/Fe/ Mg/Nd/Fe/ Mg/Nd/Fe/ Mg/Nd/Fe/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO Rb/Sr Rb/Sr/ Rb/Sr/ Rb/Sr/ Rb/Sr/ Ln1_(4−x)Ln2_(x)O₆ La_(4−x)Ln1_(x)O₆ Y₂O₃ MgO *Ln1 and Ln2 are each independently a lanthanide element, wherein Ln1 and Ln2 are not the same and x is a number ranging from greater than 0 to less than 4

As used in Tables 1-12 and throughout the specification, a nanowire composition represented by E¹/E²/E³, etc., wherein E¹, E² and E³ are each independently an element or a compound comprising one or more elements, refers to a nanowire composition comprised of a mixture of E¹, E² and E³. E¹/E²/E³, etc. are not necessarily present in equal amounts and need not form a bond with one another. For example, a nanowire comprising Li/MgO refers to a nanowire comprising Li and MgO, for example, Li/MgO may refer to a MgO nanowire doped with Li. By way of another example, a nanowire comprising NaMnO₄/MgO refers to a nanowire comprised of a mixture of NaMnO₄ and MgO. Dopants may be added in suitable form. For example in a lithium doped magnesium oxide nanowire (Li/MgO), the Li dopant can be incorporated in the form of Li₂O, Li₂CO₃, LiOH, or other suitable forms. Li may be fully incorporated in the MgO crystal lattice (e.g., (Li,Mg)O) as well. Dopants for other nanowires may be incorporated analogously.

In some more specific embodiments, the dopant is selected from Li, Ba and Sr. In other specific embodiments, the nanowires comprise Li/MgO, Ba/MgO, Sr/La₂O₃, Ba/La₂O₃, Mn/Na₂WO₄, Mn₂O₃/Na₂WO₄, Mn₃O₄/Na₂WO₄, Mg₆MnO₈, Li/B/Mg₆MnO₈, Na/B/Mg₆MnO₈, Zr₂Mo₂O₈ or NaMnO₄/MgO.

In some other specific embodiments, the nanowire comprises a mixed oxide of Mn and Mg with or without B and with or without Li. Additional dopants for such nanowires may comprise doping elements selected from Group 1 and 2 and groups 7-13. The dopants may be present as single dopants or in combination with other dopants. In certain specific embodiments of nanowires comprising a mixed oxide of Mn and Mg with or without B and with or without Li., the dopant comprises a combination of elements from group 1 and group 8-11.

Nanowires comprising mixed oxides of Mn and Mg are well suited for incorporation of dopants because magnesium atoms can be easily substituted by other atoms as long as their size is comparable with magnesium. A family of “doped” Mg₆MnO₈ compounds with the composition M_((x))Mg_((6-x))MnO₈, wherein each M is independently a dopant as defined herein and x is 0 to 6, can thus be created. The oxidation state of Mn can be tuned by selecting different amounts (i.e., different values of x) of M with different oxidation states, for example Li_((x))Mg_((6-x))MnO₈ would contain a mixture of Mn(IV) and Mn(V) with x<1 and a mixture that may include Mn(V), Mn(VI), Mn(VII) with x>1. The maximum value of x depends on the ability of a particular atom M to be incorporated in the Mg₆MnO₈ crystal structure and therefore varies depending on M. It is believed that the ability to tune the manganese oxidation state as described above could have advantageous effect on the catalytic activity of the disclosed nanowires.

Examples of nanowires comprising Li/Mn/Mg/B and an additional dopant include; Li/Mn/Mg/B doped with Co; Li/Mn/Mg/B doped with Na, Li/Mn/Mg/B doped with Be; Li/Mn/Mg/B doped with Al; Li/Mn/Mg/B doped with Hf; Li/Mn/Mg/B doped with Zr; Li/Mn/Mg/B doped with Zn; Li/Mn/Mg/B doped with Rh and Li/Mn/Mg/B doped with Ga. Nanowires comprising Li/Mn/Mg/B doped with different combinations of these dopants are also provided. For example, in some embodiments the Li/Mn/Mg/B nanowires are doped with Na and Co. In other embodiments, the Li/Mn/Mg/B nanowires are doped with Ga and Na.

In other embodiments, nanowires comprising Mn/W with or without dopants are provided. For example, the present inventors have found through high throughput testing that nanowires comprising Mn/W and various dopants are good catalysts in the OCM reaction. Accordingly, in some embodiments, the Mn/W nanowires are doped with Ba. In other embodiments, the Mn/W nanowires are doped with Be. In yet other embodiments, the Mn/W nanowires are doped with Te.

In any of the above embodiments, the Mn/W nanowires may comprise a SiO₂ support. Alternatively, the use of different supports such as ZrO₂, HfO₂ and In₂O₃ in any of the above embodiments has been shown to promote OCM activity at reduced temperature compared to the same catalyst supported on silica with limited reduction in selectivity.

Nanowires comprising rare earth oxides doped with various elements are also effective catalysts in the OCM reaction. In certain specific embodiments, the rare earth oxide or oxy-hydroxide can be any rare earth, preferably La, Nd, Eu, Sm, Yb, Gd. In certain embodiments of the nanowires comprising rare earth elements or yttria, the dopant comprises alkali earth (group 2) elements. The degree of effectiveness of a particular dopant is a function of the rare earth used and the concentration of the alkali earth dopant. In addition to Alkali earth elements, further embodiments of the rare earth or yttria nanowires include embodiments wherein the nanowires comprise alkali elements as dopants, which further promote the selectivity of the OCM catalytic activity of the doped material. In yet other embodiments of the foregoing, the nanowires comprise both an alkali element and alkali earth element as dopant. In still further embodiments, an additional dopant can be selected from an additional rare earth and groups 3, 4, 8, 9, 10, 13, 14.

The foregoing rare earth catalyst may be doped prior to, or after formation of the rare earth oxide. In one embodiment, the corresponding rare earth salt is mixed with the corresponding dopant salt to form a solution or a slurry which is dried and then calcined in a range of 400° C. to 900° C., or between 500° C. and 700° C. In another embodiment, the rare earth oxide is formed first through calcination of a rare earth salt and then contacted with a solution comprising the doping element prior to drying and calcination between 300° C. and 800° C., or between 400° C. and 700° C.

In other embodiments, the nanowires comprise La₂O₃ or LaO_(y)(OH)_(x), wherein y ranges from 0 to 1.5, x ranges from 0 to 3 and 2y+x=3, doped with Na, Mg, Ca, Sr, Ga, Sc, Y, Zr, In, Nd, Eu, Sm, Ce, Gd or combinations thereof. In yet further embodiments, the La₂O₃ or LaO_(y)(OH)_(x) nanowires are doped with binary dopant combinations, for example Eu/Na; Eu/Gd; Ca/Na; Eu/Sm; Eu/Sr; Mg/Sr; Ce/Mg; Gd/Sm, Mg/Na, Mg/Y, Ga/Sr, Nd/Mg, Gd/Na or Sm/Na. In some other embodiments, the La₂O₃ or LaO_(y)(OH)_(x) nanowires are doped with a ternary dopant combination, for example Ca—Mg—Na.

In other embodiments, the nanowires comprise Nd₂O₃ or NdO_(y)(OH)_(x), wherein y ranges from 0 to 1.5, x ranges from 0 to 3 and 2y+x=3, doped with Sr, Ca, Rb, Li, Na or combinations thereof. In certain other embodiments, the Nd₂O₃ or NdO_(y)(OH)_(x) nanowires are doped with binary dopant combinations, for example Ca/Sr, Rb/Sr, Ta/Sr or Al/Sr.

In still other examples of doped nanowires, the nanowires comprise Yb₂O₃ or YbO_(y)(OH)_(x), wherein y ranges from 0 to 1.5, x ranges from 0 to 3 and 2y+x=3, doped with Sr, Ca, Ba, Nd or combinations thereof. In certain other embodiments, the Yb₂O₃ or YbO_(y)(OH)_(x) OCM nanowires are doped with a binary combination, for example of Sr/Nd.

Still other examples of doped nanowires Eu₂O₃ or EuO_(y)(OH)_(x) nanowires, wherein y ranges from 0 to 1.5, x ranges from 0 to 3 and 2y+x=3, doped with Sr, Ba, Sm, Gd, Na or combinations thereof or a binary dopant combination, for example Sr/Na or Sm/Na.

Example of dopants for Sm₂O₃ or SmO_(y)(OH)_(x) nanowires, wherein x and y are each independently an integer from 1 to 10, include Sr, and examples of dopants for Y₂O₃ or YO_(y)(OH)_(x) nanowires, wherein y ranges from 0 to 1.5, x ranges from 0 to 3 and 2y+x=3, comprise Ga, La, Nd or combinations thereof. In certain other embodiments, the Y₂O₃ or YO_(y)(OH)_(x) nanowires comprise a binary dopant combination, for example Sr/Nd, Eu/Y or Mg/Nd or a tertiary dopant combination, for example Mg/Nd/Fe.

In yet other embodiments, the nanowires comprise Ln₂O₃ or Ln_(z)O_(y)(OH)_(x), wherein Ln is at each occurrence, independently a lanthanide, x ranges from 0 to 3 and 2y+x=3, y ranges from 0 to 1.5, and z is 1, 2 or 3, and the nanowires are doped with Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ti, Zr, Hf, V, Nb, Ta, Mo, W, Mn, Ni, Pd, Pt, Cu, Ag, Au, Zn, Al, Ga, In, TI, Ge, Sn, Pb, P, As, Sb, Bi, S, Se, Te or combinations thereof. In certain other embodiments, the Ln₂O₃ or Ln_(z)O_(y)(OH)_(x) nanowires comprise only one dopant, for example Sr, a binary dopant combination, for example Na/Mg, Na/Sr, Mg/Sr, Li/Cs, Sr/W, Hf/Bi, Na/Eu, Zn/K, Sb/Ag, Sr/Ta, a tertiary dopant combination, for example Li/Na/Sr, Na/La/Eu, Li/Sr/Cs, Dy/Rb/Gd, Mg/La/K, or a quaternary dopant combination, for example Na/Zr/Eu/Ca, Na/La/Eu/In, Na/K/Mg/Tm, Li/Cs/Sr/Tm, Ba/Tm/Zn/K, Mg/La/Yb/Zn.

Rare earth nanowires, which without doping often have low OCM selectivity, can be greatly improved by doping to reduce their combustion activity. In particular, nanowires comprising CeO₂ and Pr₂O₃ tend to have strong total oxidation activity for methane, however doping with additional rare earth elements can significantly moderate the combustion activity and improve the overall utility of the catalyst. Example of dopants for improving the selectivity for Pr₂O₃ or PrO_(y)(OH)_(x) nanowires, wherein y ranges from 0 to 1.5, x ranges from 0 to 3 and 2y+x=3, comprise binary dopants, for example Nd/Mg, La/Mg or Yb/Sr.

In some embodiments, dopants are present in the nanowires in, for example, less than 50 at %, less than 25 at %, less than 10 at %, less than 5 at % or less than 1 at %.

In other embodiments of the nanowires, the atomic ratio (w/w) of the one or more metal elements selected from Groups 1-7 and lanthanides and actinides in the form of an oxide and the dopant ranges from 1:1 to 10,000:1, 1:1 to 1,000:1 or 1:1 to 500:1.

In further embodiments, the nanowires comprise one or more metal elements from Group 2 in the form of an oxide and a dopant from Group 1. In further embodiments, the nanowires comprise magnesium and lithium. In other embodiments, the nanowires comprise one or more metal elements from Group 2 and a dopant from Group 2, for example, in some embodiments, the nanowires comprise magnesium oxide and barium. In other embodiments, the nanowires comprise one or more metal elements from Group 2, a dopant from Group 2 and an additional dopant, for example, in some embodiments, the nanowires comprise magnesium oxide and are doped with strontium and tungsten dopants (i.e., Sr/W/MgO). In another embodiment, the nanowires comprise an element from the lanthanides in the form of an oxide and a dopant from Group 1 or Group 2. In further embodiments, the nanowires comprise lanthanum and strontium.

Various methods for preparing doped nanowires are provided. In one embodiment, the doped nanowires can be prepared by co-precipitating a nanowire metal oxide precursor and a dopant precursor. In these embodiments, the doping element may be directly incorporated into the nanowire.

Template Directed Synthesis of Nanowires

In some embodiments, the nanowires can be prepared in a solution phase using an appropriate template. In this context, an appropriate template can be any synthetic or natural material, or combination thereof, that provides nucleation sites for binding ions (e.g. metal element ions and/or hydroxide or other anions) and causing the growth of a nanowire. The templates can be selected such that certain control of the nucleation sites, in terms of their composition, quantity and location can be achieved in a statistically significant manner. The templates are typically linear or anisotropic in shape, thus directing the growth of a nanowire.

In contrast to other template directed preparation of nanostructures, the nanowires of the invention are generally not prepared from nanoparticles deposited on a template in a reduced state which are then heat treated and fused into an elongated nanoporous nanostructure. In particular, such methods are not generally applicable to continuous nanowires comprising one or more elements from any of Groups 1 through 7, lanthanides, actinides or combinations thereof. Instead of forming a plurality of catalyst nanoparticles, nanocrystals, or nanocrystallites on the surface of the template, the nanowires of the invention are preferably prepared by nucleation of an oxidized metal element (e.g., in the form of a metal ion) and subsequent growth of a nanowire. After nucleation of the oxidized metal element, the nanowires are generally calcined to produce the desired oxide, but annealing of nanoparticles is not necessary to form the nanowires.

Accordingly, the nanowires used in the context of the invention have a number of properties that differentiate them from other nanostructures, such as those created as fused aggregates of nanoparticles. In particular, the nanowires are characterized as having one or more of; a substantially non-nanoporous structure, an average crystal domain size, either before and/or after calcination, of greater than 5 nm, and an anisotropic crystal habit.

In the context of non-nanoporous nanowires, preferred compositions are distinguished from elongated nanostructures formed as nanoporous aggregates of nanoparticles by virtue of their substantially non-nanoporous structures. Such substantially non-nanoporous nanowire structures will preferably have a surface area of less than 150 m²/g, more preferably less than 100 m²/g, less than 50 m²/g, less than 40 m²/g, less than 30 m²/g less than 25 m²/g, less than 20 m²/g, less than 15 m²/g, less than 10 m²/g, or between 1 m²/g and any of the foregoing. As will be appreciated, nanowires created through templating processes, where additional aggregates may fuse to a non-nanoporous or substantially non-nanoporous nanowire core, will typically have higher surface areas, e.g., surface areas toward the higher end of the range, while nanowires created from other processes, e.g., by hydrothermal processes, will typically have lower surface areas.

In certain aspects, the nanowires of the invention are characterized by relatively large crystal domain sizes in the context of relatively high surface area nanowire structures. In particular, and as noted previously, for those nanowires of the invention having an average crystal domain size in at least one crystal dimension that is greater than 5 nm, preferred nanowires of the invention will typically have an average crystal domain size in at least one crystal dimension that is greater than 10 nm, and in more preferred aspects, greater than 20 nm.

In certain embodiments, the nanowires of the invention may also be characterized by additional structural properties. For example, in certain aspects, the nanowires of the invention may be characterized by a continuous crystal structure within the nanowire, excluding stacking faults. In certain aspects, the nanowires of the invention may be characterized by an aligned crystal structure within the nanowire consisting of parallel, aligned crystal domains.

In some embodiments, methods for forming nanowires having the empirical formula M4_(w)M5_(x)M6_(y)O_(z) are provided, wherein M4 comprises one or more elements selected from Groups 1 through 4, M5 comprises one or more elements selected from Group 7 and M6 comprises one or more elements selected from Groups 5 through 8 and Groups 14 through 15 and w, x, y and z are integers such that the overall charge is balanced. The methods comprise combining one or more sources of M4, one or more sources of M5, and one or more sources of M6 in the presence of a templating agent and a solvent to form a mixture. In certain embodiments the templating agent is a polymer, for example PVP (polyvinlpyrrolidone), PVA (polyvinylalcohol), PEI (polyethyleneimine), PEG (polyethyleneglycol), polyether, polyesters, polyamides, dextran and other sugar polymers, functionalized hydrocarbon polymers, functionalized polystyrene, polylactic acid, polycaprolactone, polyglycolic acid, poly(ethylene glycol)-poly(propylene glycol)-poly(ethylene glycol), copolymers or combinations thereof.

In certain embodiments, M4 includes one or more elements selected from Group 1, such as Na, while M6 includes one or more elements selected from Group 6, such as W and M3 is Mn. In one embodiment, M4 is Na and the source of M4 is NaCl, M5 is Mn and the source of M5 is Mn(NO₃)₂, M6 is W and the source of M6 is WO₃, the solvent is water, and the templating agent is a polymer, for example PVP (polyvinlpyrrolidone), PVA (polyvinylalcohol), PEI (polyethyleneimine), PEG (polyethyleneglycol), polyether, polyesters, polyamides, dextran and other sugar polymers, functionalized hydrocarbon polymers, functionalized polystyrene, polylactic acid, polycaprolactone, polyglycolic acid, poly(ethylene glycol)-poly(propylene glycol)-poly(ethylene glycol), copolymers or combinations thereof.

In various embodiments, the source of M4 can be one or more of a chloride, bromide, iodide, oxychloride, oxybromide, oxyiodide, nitrate, oxynitrate, sulfate or phosphate salt of any of Group 1, Group 2, Group 3, or a Group 4 element. In an embodiment, sources of M4 include LiCl, KCl, MgCl₂, CaCl₂, ScCl₃, TiCl₄, KBr, CaBr₂, Sc(NO₃)₃, Y(NO₃)₃, TiBr₄, ZrBr₄, Zr(NO₃)₄, ZrOCl₂, ZrO(NO₃)₂, Na₂SO₄, and Zr(SO₄)₂. For any given source of M4, a source of M6 can be one or more of an oxide, oxide salt, or an oxyacid of any of Group 5, Group 6, Group 7, Group 8, Group 14 and Group 15 elements. In an embodiment, sources of M6 include MoO₃, (NH₄)₆Mo₇O₂₄, WO₃, Na₂WO₄, H₂WO₄, Co₂O₃, P₂O₅, H₃PO₄ and H₂SiO₄. For any given combination of a source of M4 and a source of M6, a source of Mn can be, but is not limited to, any chloride, bromide, nitrate, or sulfate of manganese, including MnCl₂, MnCl₃, MnCl₄, Mn(NO₃)₃, MnSO₄ and Mn₂(SO₄)₃.

In still other embodiments, the templating agent can include a surfactant, such as tetraoctylammonium chloride, ammonium lauryl sulfate, or lauryl glucoside. For any templating agent or any source of M4, M6, or Mn, the solvent can include an organic solvent, such as ethanol, diethyl ether, or acetonitrile. Additionally, any embodiment of the method for forming a nanowire described above can include any additional component in the reaction mixture, such as a base.

Nanowire-forming methods of various embodiments of the invention comprise combining a source of M4, a source of M5, a source of M6, a templating agent (e.g., polymer), and a solvent in a reaction mixture. In other embodiments, however, nanowire-forming methods of the present invention comprise combining two of a source of M4, a source of M5 and a source of M6 in the presence of a templating agent and a solvent to form an intermediate nanowire and then combining a remainder of the source of M4, the source of M5 and the source of M6 with the intermediate nanowire, wherein M4 includes one or more elements selected from Group 1, Group 2, Group 3 and Group 4 elements, wherein M5 includes one or more elements selected from Group 7, and wherein M6 includes one or more elements selected from Group 5, Group 6, Group 7, Group 8, Group 14 and Group 15 elements. In an embodiment, an intermediate nanowire is formed by combining the source of M5 and the source of M6 in the presence of the templating agent and the solvent, followed by combining the intermediate nanowire with the source of M4.

1. Polymer Template

As discussed above, the present disclosure provides nanowires and methods for preparing the same via polymer template methods. Polymer or “soft” templates have extensively been used in materials synthesis to prepare materials with unique nano and microstructures. Polymer templated materials may have irregular, ordered, or shape specific structures. To a large extent, the resulting structure is predicated on the interaction of the polymer and the inorganic material to be templated. For example, changing the polymer templating agent while leaving the metal precursor the same can have drastic effects on the metal/metal oxide end structure. The ability to tune the metal/metal oxide structure to achieve a desired catalytic performance has been an ongoing goal in the field of catalysis. Thus, the presently disclosed methods find utility in for preparation of carious catalytic structures, for example nanowires.

Polymers can be used to prepare templated and textured metal oxide OCM catalysts, for example in the form of nanowires. This invention describes a simple method to prepare metal and mixed metal oxide OCM catalysts using polymer templates. In one embodiment, the disclosed methods employ polymers (e.g., water-soluble polymers) with a wide range of molecular weights, as the templating source. Exemplary polymers include PVP (polyvinlpyrrolidone), PVA (polyvinylalcohol), PEI (polyethyleneimine), PEG (polyethyleneglycol), polyether, polyesters, polyamides, dextran and other sugar polymers, functionalized hydrocarbon polymers, functionalized polystyrene, polylactic acid, polycaprolactone, polyglycolic acid, poly(ethylene glycol)-poly(propylene glycol)-poly(ethylene glycol) and copolymers and combinations thereof. In some embodiments, the polymer template is functionalized with at least one of amine, carboxylic acid, sulfate, alcohol, halogen or thiol groups. For example the polymer template may be a hydrocarbon or polystyrene polymer functionalized with at least one of amine, carboxylic acid, sulfate, alcohol halogen or thiol groups.

Briefly, a metal precursor and polymer are dissolved in water to produce a viscous solution. The solution is dried and calcined (oven or microwave) to remove the polymer template. In some embodiments, multiple metal (e.g., M1, M2, etc.) precursors are dissolved in a polymer solution. The solution is dried and calcined as described above to yield mixed metal oxide systems for OCM catalysis. Another embodiment uses freeze drying to dry the polymer/metal solution to prepare a more controllable porosity in the metal and mixed metal oxide materials.

Some embodiments comprise use of polymers that readily form gels to prepare metal oxides and mixed metal oxides for OCM catalysts. For example, agarose readily forms a gel that can be used as a templating source by impregnating the gel with metal precursors. One embodiment of the present disclosure comprises impregnating a gel (e.g., agarose) with one or more metal precursors to prepare a nanowire comprising one or more metals, for example a metal oxide or mixed metal oxide. The gel may be impregnated with multiple metals in one step or via a step wise impregnation.

In another embodiment, the disclosed methods comprise treating a metal-polymer gel composite (e.g., agarose) with a base to precipitate the metal precursors within the gel framework. The precipitated metals may then optionally be calcined. Another embodiment uses freeze drying to remove the water from the metal-polymer gel composite. The agarose is removed by oven or microwave calcination to yield metal and mixed metal OCM catalysts.

The “Pechini” Method is a convenient method to prepare evenly dispersed mixed metal oxides. The general procedure comprises use of a multifunctional coordinating ligand that chelates to the metal in solution to create a metal coordination complex that can be polymerized in-situ, using a polyalcohol, to prepare a metal/organic composite. Normally an alpha-hydroxycarboxylic acid, such as citric acid, is used to form a stable metal complex and can be esterified/cross-linked with a poly-hydroxyalcohol, such as ethylene glycol or glycerol, to form a polymeric resin. Immobilization of the metal complexes in the resin reduces metal segregation and facilitates compositional homogeneity.

2. Nucleation

Nucleation is the process of forming an inorganic nanowire in situ by converting soluble precursors (e.g., metal salts and anions) into nanocrystals in the presence of a template (e.g., a polymer template). Typically, the nucleation and growth takes place from multiple binding sites along the length of the polymer template in parallel. The growth continues until a structure encasing the polymer template is formed. In some embodiments this structure is single-crystalline. In other embodiments the structure is amorphous, and in other embodiments the structure is polycrystalline. If desired, upon completion of the synthesis the polymer template can be removed by thermal treatment (˜300° C.) in air or oxygen, without significantly affecting either the structure or shape of the inorganic material. In addition, dopants can be either simultaneously incorporated during the growth process or, in another embodiment, dopants can be incorporated via impregnation techniques.

(a) Nanowire Growth Methods

FIG. 6 shows a flow chart of a nucleation process for forming a nanowire comprising a metal oxide. A polymer solution is first prepared (block 5O4), to which metal salt precursor comprising metal ions is added (block 510). Thereafter, an anion precursor is added (block 520). It is noted that, in various embodiments, the additions of the metal ions and anion precursor can be simultaneous or sequentially in any order. Under appropriate conditions (e.g., pH, molar ratio of the polymer and metal salt, molar ratio of the metal ions and anions, addition rate, etc.), the metal ions and anions become bound to the polymer, nucleate and grow into a nanowire of M_(m)X_(n)Z_(p) composition (block 524). Following calcinations, nanowires comprising M_(m)X_(n) are transformed to nanowires comprising metal oxide (M_(x)O_(y)) (block 530). An optional step of doping (block 534) incorporates a dopant (D^(P+)) in the nanowires comprising metal oxide (M_(x)O_(y), wherein x and y are each independently a number from 1 to 100. For ease of illustration, FIG. 6 depicts calcinations prior to doping; however, in certain embodiments doping may be performed prior to calcinations.

Thus, one embodiment provides a method for preparing a nanowire comprising a metal oxide, a metal oxy-hydroxide, a metal oxycarbonate or a metal carbonate, the method comprising:

a) providing a solution comprising a plurality of polymer templates;

(b) introducing at least one metal ion and at least one anion to the solution under conditions and for a time sufficient to allow for nucleation and growth of a nanowire comprising a plurality of metal salts (M_(m)X_(n)Z_(p)) on the template; and

(c) converting the nanowire (M_(m)X_(n)Z_(p)) to a metal oxide nanowire comprising a plurality of metal oxides (M_(x)O_(y)), metal oxy-hydroxides (M_(x)O_(y)OH_(z)), metal oxycarbonates (M_(x)O_(y)(CO₃)_(z)), metal carbonate (M_(x)(CO₃)_(y)) or combinations thereof

wherein:

M is, at each occurrence, independently a metal element from any of Groups 1 through 7, lanthanides or actinides;

X is, at each occurrence, independently hydroxide, carbonate, bicarbonate, phosphate, hydrogenphosphate, dihydrogenphosphate, sulfate, nitrate or oxalate;

Z is O;

n, m, x and y are each independently a number from 1 to 100; and

p is a number from 0 to 100.

In some embodiments of the foregoing, the polymer template comprises PVP (polyvinlpyrrolidone), PVA (polyvinylalcohol), PEI (polyethyleneimine), PEG (polyethyleneglycol), polyether, polyesters, polyamides, dextran and other sugar polymers, functionalized hydrocarbon polymers, functionalized polystyrene, polylactic acid, polycaprolactone, polyglycolic acid, poly(ethylene glycol)-poly(propylene glycol)-poly(ethylene glycol), copolymers or combinations thereof. In some embodiments, the polymer template is functionalized with at least one of amine, carboxylic acid, sulfate, alcohol, halogen or thiol groups. For example the polymer template may be a hydrocarbon or polystyrene polymer functionalized with at least one of amine, carboxylic acid, sulfate, alcohol, halogen or thiol groups.

In some embodiments, the nanowire is dried in an oven, while in other embodiments the nanowire is freeze dried or air dried. The drying method may have an effect on the final morphology, pore size, etc. of the resulting nanowire. Additionally, the solution comprising the polymer template may be in the form of a gel and the at least one metal ion is impregnated therein. The gel may then be dried as described above. In some embodiments, the metal impregnated gel is treated with a base to precipitate the metal. In some different embodiments, the polymer template is removed from the nanowire by heat treatment or other removal means.

In certain other variations of the foregoing, two or more different metal ions may be used. This produces nanowires comprising a mixture of two or more metal oxides. Such nanowires may be advantageous in certain catalytic reactions. For example, in some embodiments the nanowire catalysts may comprise at least a first and second metal oxide wherein the first metal oxide has better OCM activity than the second metal oxide and the second metal oxide has better ODH activity than the first metal oxide. In certain embodiments of the above, Applicants have found that it may be advantageous to perform multiple sequential additions of the metal ion, This addition technique may be particularly applicable to embodiments wherein two or more different metal ions are employed to form a mixed nanowire (M1M2X_(x)Y_(y), wherein M1 and M2 are different metal elements), which can be converted to M1M2O_(z), for example by calcination. The slow addition may be performed over any period of time, for example from 1 day to 1 week. In this regard, use of a syringe pump or an automatic (e.g., robotic) liquid dispenser may be advantageous. Slow addition of the components help ensure that they will nucleate on the polymer template instead of non-selectively precipitate.

In various embodiments, the polymer templates are selected from PVP (polyvinlpyrrolidone), PVA (polyvinylalcohol), PEI (polyethyleneimine), PEG (polyethyleneglycol), polyether, polyesters, polyamides, dextran and other sugar polymers, functionalized hydrocarbon polymers, functionalized polystyrene, polylactic acid, polycaprolactone, polyglycolic acid, poly(ethylene glycol)-poly(propylene glycol)-poly(ethylene glycol), copolymers or combinations thereof. In some embodiments, the polymer template is functionalized with at least one of amine, carboxylic acid, sulfate, alcohol, halogen or thiol groups. For example the polymer template may be a hydrocarbon or polystyrene polymer functionalized with at least one of amine, carboxylic acid, sulfate, alcohol, halogen or thiol groups.

In further embodiments, the metal ion is provided by adding one or more metal salt (as described herein) to the solution. In other embodiments, the anion is provided by adding one or more anion precursor to the solution. In various embodiments, the metal ion and the anion can be introduced to the solution simultaneously or sequentially in any order. In some embodiments, the nanowire (M_(m)X_(n)Z_(p)) is converted to a metal oxide nanowire by calcination, which is a thermal treatment that transforms or decomposes the M_(m)X_(n)Z_(p) nanowire to a metal oxide. In yet another embodiment, the method further comprises doping the metal oxide nanowire with a dopant. Doping may be performed either before or after calcination. Converting the nanowire to a metal oxide (or oxy-hydroxide, oxy-carbonate, or carbonate, etc.) generally comprises calcining.

In a variation of the above method, mixed metal oxides can be prepared (as opposed to a mixture of metal oxides). Mixed metal oxides can be represented by the following formula M1_(w)M2_(x)M3_(y)O_(z), wherein M1, M2 and M3 are each independently absent or a metal element, and w, x, y and z are integers such that the overall charge is balanced. Mixed metal oxides comprising more than three metals are also contemplated and can be prepared via an analogous method. Such mixed metal oxides find utility in a variety of the catalytic reactions disclosed herein. One exemplary mixed metal oxide is Na₁₀MnW₅O₁₇.

Thus, one embodiment provides a method for preparing a mixed metal oxide nanowire comprising a plurality of mixed metal oxides (M1_(w)M2_(x)M3_(y)O_(z)), the method comprising:

a) providing a solution comprising a plurality of polymer templates;

(b) introducing metal salts comprising M1, M2 and M3 to the solution under conditions and for a time sufficient to allow for nucleation and growth of a nanowire comprising a plurality of the metal salts on the template; and

(c) converting the nanowire to a mixed metal oxide nanowire comprising a plurality of mixed metal oxides (M1_(w)M2_(x)M3_(y)O_(z)),

wherein:

M1, M2 and M3 are, at each occurrence, independently a metal element from any of Groups 1 through 7, lanthanides or actinides;

n, m, x and y are each independently a number from 1 to 100; and

p is a number from 0 to 100.

In some embodiments of the foregoing, the polymer template comprises PVP (polyvinlpyrrolidone), PVA (polyvinylalcohol), PEI (polyethyleneimine), PEG (polyethyleneglycol), polyether, polyesters, polyamides, dextran and other sugar polymers, functionalized hydrocarbon polymers, functionalized polystyrene, polylactic acid, polycaprolactone, polyglycolic acid, poly(ethylene glycol)-poly(propylene glycol)-poly(ethylene glycol), copolymers or combinations thereof. In some embodiments, the polymer template is functionalized with at least one of amine, carboxylic acid, sulfate, alcohol, halogen or thiol groups. For example the polymer template may be a hydrocarbon or polystyrene polymer functionalized with at least one of amine, carboxylic acid, sulfate, alcohol or thiol groups.

In some embodiments, the nanowire is dried in an oven, while in other embodiments the nanowire is freeze dried or air dried. The drying method may have an effect on the final morphology, pore size, etc. of the resulting nanowire. Additionally, the solution comprising the polymer template may be in the form of a gel and the at least one metal salts are impregnated therein. The gel may then be dried as described above. In some embodiments, the metal impregnated gel is treated with a base to precipitate the metal. In some different embodiments, the polymer template is removed from the nanowire by heat treatment or other removal means.

In other embodiments, the present disclosure provides a method for preparing metal oxide nanowires which may not require a calcination step. Thus, in some embodiments the method for preparing metal oxide nanowires comprises:

(a) providing a solution that includes a plurality of polymer templates; and

(b) introducing a compound comprising a metal to the solution under conditions and for a time sufficient to allow for nucleation and growth of a nanowire (M_(m)Y_(n)) on the template;

wherein:

M is a metal element from any of Groups 1 through 7, lanthanides or actinides;

Y is O;

n and m are each independently a number from 1 to 100.

In some embodiments of the foregoing, the polymer template comprises PVP (polyvinlpyrrolidone), PVA (polyvinylalcohol), PEI (polyethyleneimine), PEG (polyethyleneglycol), polyether, polyesters, polyamides, dextran and other sugar polymers, functionalized hydrocarbon polymers, functionalized polystyrene, polylactic acid, polycaprolactone, polyglycolic acid, poly(ethylene glycol)-poly(propylene glycol)-poly(ethylene glycol), copolymers or combinations thereof. In some embodiments, the polymer template is functionalized with at least one of amine, carboxylic acid, sulfate, alcohol, halogen or thiol groups. For example the polymer template may be a hydrocarbon or polystyrene polymer functionalized with at least one of amine, carboxylic acid, sulfate, alcohol, halogen or thiol groups.

In some embodiments, the nanowire is dried in an oven, while in other embodiments the nanowire is freeze dried or air dried. The drying method may have an effect on the final morphology, pore size, etc. of the resulting nanowire. Additionally, the solution comprising the polymer template may be in the form of a gel and the at least one metal is impregnated therein. The gel may then be dried as described above. In some embodiments, the metal impregnated gel is treated with a base to precipitate the metal. In some different embodiments, the polymer template is removed from the nanowire by heat treatment or other removal means.

In some specific embodiments of the foregoing method, M is an early transition metal, for example V, Nb, Ta, Ti, Zr, Hf, W, Mo or Cr. In other embodiments, the metal oxide is WO₃. In yet another embodiment, the method further comprises doping the metal oxide nanowire with a dopant. In some further embodiments, a reagent is added which converts the compound comprising a metal into a metal oxide.

In another embodiment the disclosure provides a method for preparing a nanowire comprising a metal oxide, a metal oxy-hydroxide, a metal oxycarbonate or a metal carbonate, the method comprises:

a) providing a solution comprising a plurality of a multifunctional coordinating ligand;

(b) introducing at least one metal ion to the solution, thereby forming a metal ion-ligand complex;

(c) introducing a polyalcohol to the solution, wherein the polyalcohol polymerizes with the metal-ion ligand complex to form a polymerized metal ion-ligand complex.

In some embodiments, the multifunctional coordinating ligand is an alpha-hydroxycarboxylic acid, for example citric acid. In other embodiments, the polyalcohol is ethylene glycol or glycerol. In yet other embodiments, the method further comprises heating the polymerized metal ion-ligand complex to remove substantially all organic material, and optionally heating the remaining inorganic metal to convert it to a metal oxide (i.e., calcine). In another embodiment, nanowires are prepared by using metal salts sensitive to water hydrolysis, for example NbCl₅, WCl₆, TiCl₄, ZrCl₄. A polymer template can be placed in ethanol along with the metal salt. Water is then slowly added to the reaction in order to convert the metals salts to metal oxide coated template.

By varying the nucleation conditions, including (without limitation): incubation time of polymer and metal salt; incubation time of polymer and anion; concentration of polymer; metal ion concentration, anion concentration, sequence of adding anion and metal ions; pH; polymer composition; polymer size; solution temperature in the incubation step and/or growth step; types of metal precursor salt; types of anion precursor; addition rate; number of additions; amount of metal salt and/or anion precursor per addition, the time that lapses between the additions of the metal salt and anion precursor, including, e.g., simultaneous (zero lapse) or sequential additions followed by respective incubation times for the metal salt and the anion precursor, stable nanowires of diverse compositions and surface properties can be prepared. For example, in certain embodiments the pH of the nucleation conditions is at least 7.0, at least 8.0, at least 9.0, at least 10.0, at least 11.0, at least 12.0 or at least 13.0.

As noted above, the rate of addition of reactants (e.g., metal salt, metal oxide, anion precursor, etc.) is one parameter that can be controlled and varied to produce nanowires having different properties. During the addition of reactants to a solution containing an existing nanowire and/or a templating material, a critical concentration is reached for which the speed of deposition of solids on the existing nanowire and/or templating material matches the rate of addition of reactants to the reaction mixture. At this point, the concentration of soluble cation stabilizes and stops rising. Thus, nanowire growth can be controlled and maximized by maintaining the speed of addition of reactants such that near super-saturation concentration of the cation is maintained. This helps ensure that no undesirable nucleation occurs. If super-saturation of the anion (e.g., hydroxide) is exceeded, a new solid phase can start nucleating which allows for non-selective solid precipitation, rather than nanowire growth. Thus, in order to selectively deposit an inorganic layer on an existing nanowire and/or a templating material, the addition rate of reactants should be controlled to avoid reaching super-saturation of the solution containing the suspended solids.

Accordingly, in one embodiment, reactant is repeatedly added in small doses to slowly build up the concentration of the reactant in the solution containing the template. In some embodiments, the speed of addition of reactant is such that the reactant concentration in the solution containing the template is near (but less than) the saturation point of the reactant. In some other embodiments, the reactant is added portion wise (i.e., step addition) rather than continuously. In these embodiments, the amount of reactant in each portion, and the time between addition of each portion, is controlled such that the reactant concentration in the solution containing the template is near (but less than) the saturation point of the reactant. In certain embodiments of the foregoing, the reactant is a metal cation while in other embodiments the reactant is an anion.

Initial formation of nuclei on a template can be obtained by the same method described above, wherein the concentration of reactant is increased until near, but not above, the supersaturation point of the reactant. Such an addition method facilitates nucleation of the solid phase on the template, rather than homogeneous non-seeding nucleation. In some embodiments, it is desirable to use a slower reactant addition speed during the initial nucleation phase as the super-saturation depression due to the template might be quite small at this point. Once the first layer of solid (i.e., nanowire) is formed on the template, the addition speed can be increased.

In some embodiments, the addition rate of reactant is controlled such that the precipitation rate matches the addition rate of the reactant. In these embodiments, nanowires comprising two or more different metals can be prepared by controlling the addition rates of two or more different metal cation solutions such that the concentration of each cation in the templating solution is maintained at or near (but does not exceed) the saturation point for each cation.

In some embodiments, the optimal speed of addition (and step size if using step additions) is controlled as a function of temperature. For example, in some embodiments the nanowire growth rate is accelerated at higher temperatures. Thus, the addition rate of reactants is adjusted according to the temperature of the templating solution.

In other embodiments, modeling (iterative numeric rather than algebraic) of the nanowire growth process is used to determine optimal solution concentrations and supernatant re-cycling strategies.

As noted above, the addition rate of reactants can be controlled and modified to change the properties of the nanowires. In some embodiments, the addition rate of a hydroxide source must be controlled such that the pH of the templating solution is maintained at the desired level. This method may require specialized equipment, and depending on the addition rate, the potential for localized spikes in pH upon addition of the hydroxide source is possible. Thus, in an alternative embodiment the present disclosure provides a method wherein the template solution comprises a weak base that slowly generates hydroxide in-situ, obviating the need for an automated addition sequence.

In the above embodiment, organic epoxides, such as but not limited to propylene oxide and epichlorohydrin, are used to slowly increase the template solution pH without the need for automated pH control. The epoxides are proton scavengers and undergo an irreversible ring-opening reaction with a nucleophilic anion of the metal oxide precursor (such as but not limited to Cl⁻ or NO₃ ⁻). The net effect is a slow homogenous raise in pH to form metal hydroxy species in solution that deposit onto the template surface. In some embodiments, the organic epoxide is propylene oxide.

An attractive feature of this method is that the organic epoxide can be added all at once, there is no requirement for subsequent additions of organic epoxide to grow metal oxide coatings over the course of the reaction. Due to the flexibility of the “epoxide-assisted” coatings, it is anticipated that many various embodiments can be employed to make new templated materials (e.g., nanowires). For example, mixed metal oxide nanowires can be prepared by starting with appropriate ratios of metal oxide precursors and propylene oxide in the presence of polymer template. In other embodiments, metal oxide deposition on the polymer template can be done sequentially to prepare core/shell materials (described in more detail below).

(b) Metal Salt

As noted above, the nanowires are prepared by nucleation of metal ions in the presence of an appropriate template, for example, a polymer. In this respect, any soluble metal salt may be used as the precursor of metal ions that nucleate on the template. Soluble metal salts of the metals from Groups 1 through 7, lanthanides and actinides are particularly useful and all such salts are contemplated.

In one embodiment, the soluble metal salt comprises chlorides, bromides, iodides, nitrates, sulfates, acetates, oxides, oxyhalides, oxynitrates, phosphates (including hydrogenphosphate and dihydrogenphosphate) formates, alkoxides or oxalates of metal elements from Groups 1 through 7, lanthanides, actinides or combinations thereof. In more specific embodiments, the soluble metal salt comprises chlorides, nitrates or sulfates of metal elements from Groups 1 through 7, lanthanides, actinides or combinations thereof. The present disclosure contemplates all possible chloride, bromide, iodide, nitrate, sulfate, acetate, oxide, oxyhalides, oxynitrates, phosphates (including hydrogenphosphate and dihydrogenphosphate) formates, alkoxides and oxalate salts of metal elements from Groups 1 through 7, lanthanides, actinides or combinations thereof.

In another embodiment, the metal salt comprises LiCl, LiBr, LiI, LiNO₃, Li₂SO₄, LiCO₂CH₃, Li₂C₂O₄, Li₃PO₄, Li₂HPO₄, LiH₂PO₄, LiCO₂H, LiOR, NaCl, NaBr, NaI, NaNO₃, Na₂SO₄, NaCO₂CH₃, Na₂C₂O₄, Na₃PO₄, Na₂HPO₄, NaH₂PO₄, NaCO₂H, NaOR, KCl, KBr, KI, KNO₃, K₂SO₄, KCO₂CH₃, K₂C₂O₄, K₃PO₄, K₂HPO₄, KH₂PO₄, KCO₂H, KOR, RbCl, RbBr, RbI, RbNO₃, Rb₂SO₄, RbCO₂CH₃, Rb₂C₂O₄, Rb₃PO₄, Rb₂HPO₄, RbH₂PO₄, RbCO₂H, RbOR, CsCl, CsBr, CsI, CsNO₃, Cs₂SO₄, CsCO₂CH₃, Cs₂C₂O₄, Cs₃PO₄, Cs₂HPO₄, CsH₂PO₄, CsCO₂H, CsOR, BeCl₂, BeBr₂, BeI₂, Be(NO₃)₂, BeSO₄, Be(CO₂CH₃)₂, BeC₂O₄, Be₃(PO₄)₂, BeHPO₄, Be(H₂PO₄)₂, Be(CO₂H)₂, Be(OR)₂, MgCl₂, MgBr₂, MgI₂, Mg(NO₃)₂, MgSO₄, Mg(CO₂CH₃)₂, MgC₂O₄, Mg₃(PO₄)₂, MgHPO₄, Mg(H₂PO₄)₂, Mg(CO₂H)₂, Mg(OR)₂, CaCl₂, CaBr₂, CaI₂, Ca(NO₃)₂, CaSO₄, Ca(CO₂CH₃)₂, CaC₂O₄, Mg₃(PO₄)₂, MgHPO₄, Mg(H₂PO₄)₂, Mg(CO₂H)₂, Mg(OR)₂, SrCl₂, SrBr₂, Srl₂, Sr(NO₃)₂, SrSO₄, Sr(CO₂CH₃)₂, SrC₂O₄, Sr₃(PO₄)₂, SrHPO₄, Sr(H₂PO₄)₂, Sr(CO₂H)₂, Sr(OR)₂, BaCl₂, BaBr₂, BaI₂, Ba(NO₃)₂, BaSO₄, Ba(CO₂CH₃)₂, BaC₂O₄, Ba₃(PO₄)₂, BaHPO₄, Ba(H₂PO₄)₂, Ba(CO₂H)₂, Ba(OR)₂, ScCl₃, ScBr₃, ScI₃, Sc(NO₃)₃, Sc₂(SO₄)₃, Sc(CO₂CH₃)₃, Sc₂(C₂O₄)₃, ScPO₄, Sc₂(HPO₄)₃, Sc(H₂PO₄)₃, Sc(CO₂H)₃, Sc(OR)₃, YCl₃, YBr₃, YI₃, Y(NO₃)₃, Y₂(SO₄)₃, Y(CO₂CH₃)₃, Y₂(C₂O₄)₃, YPO₄, Y₂(HPO₄)₃, Y(H₂PO₄)₃, Y(CO₂H)₃, Y(OR)₃, TiCl₄, TiBr₄, TiI₄, Ti(NO₃)₄, Ti(SO₄)₂, Ti(CO₂CH₃)₄, Ti(C₂O₄)₂, Ti₃(PO₄)₄, Ti(HPO₄)₂, Ti(H₂PO₄)₄, Ti(CO₂H)₄, Ti(OR)₄, ZrCl₄, ZrOCl₂, ZrBr₄, ZrI₄, Zr(NO₃)₄, ZrO(NO₃)₂, Zr(SO₄)₂, Zr(CO₂CH₃)₄, Zr(C₂O₄)₂, Zr₃(PO₄)₄, Zr(HPO₄)₂, Zr(H₂PO₄)₄, Zr(CO₂H)₄, Zr(OR)₄, HfCl₄, HfBr₄, HfI₄, Hf(NO₃)₄, Hf(SO₄)₂, Hf(CO₂CH₃)₄, Hf(C₂O₄)₂, Hf₃(PO₄)₄, Hf(HPO₄)₂, Hf(H₂PO₄)₄, Hf(CO₂H)₄, Hf(OR)₄, LaCl₃, LaBr₃, LaI₃, La(NO₃)₃, La₂(SO₄)₃, La(CO₂CH₃)₃, La₂(C₂O₄)₃, LaPO₄, La₂(HPO₄)₃, La(H₂PO₄)₃, La(CO₂H)₃, La(OR)₃, WCl₂, WCl₃, WCl₄, WCl₅, WCl₆, WBr₂, WBr₃, WBr₄, WBr₅, WBr₆, W₁₂, WI₃, WI₄, WI₅, WI₆, W(NO₃)₂, W(NO₃)₃, W(NO₃)₄, W(NO₃)₅, W(NO₃)₆, W(CO₂CH₃)₂, W(CO₂CH₃)₃, W(CO₂CH₃)₄, W(CO₂CH₃)₅, W(CO₂CH₃)₆, WC₂O₄, W₂(O₂O₄)₃, W(C₂O₄)₂, W₂(O₂O₄)₅, W(C₂O₄)₆, WPO₄, W₂(HPO₄)₃, W(H₂PO₄)₃, W(CO₂H)₃, W(OR)₃, W₃(PO₄)₄, W(HPO₄)₂, W(H₂PO₄)₄, W(CO₂H)₄, W(OR)₄, W₃(PO₄)₅, W₂(HPO₄)₅, W(H₂PO₄)₅, W(CO₂H)₅, W(OR)₅, W(PO₄)₂, W(HPO₄)₃, W(H₂PO₄)₆, W(CO₂H)₆, W(OR)₆, MnCl₂ MnCl₃, MnBr₂ MnBr₃, Mnl₂ Mnl₃, Mn(NO₃)₂, Mn(NO₃)₃, MnSO₄, Mn₂(SO₄)₃, Mn(CO₂CH₃)₂, Mn(CO₂CH₃)₃, MnC₂O₄, Mn₂(C₂O₄)₃, Mn₃(PO₄)₂, MnHPO₄, Mn(H₂PO₄)₂, Mn(CO₂H)₂, Mn(OR)₂, MnPO₄, Mn₂(HPO₄)₃, Mn(H₂PO₄)₃, Mn(CO₂H)₃, Mn(OR)₃, MoCl₂, MoCl₃, MoCl₄, MoCl₅, MoBr₂, MoBr₃, MoBr₄, MoBr₅, MoI₂, MoI₃, MoI₄, MoI₅, Mo(NO₃)₂, Mo(NO₃)₃, Mo(NO₃)₄, Mo(NO₃)₅, MoSO₄, Mo₂(SO₄)₃, Mo(SO₄)₂, Mo₂(SO₄)₅, Mo(CO₂CH₃)₂, Mo(CO₂CH₃)₃, Mo(CO₂CH₃)₄, Mo(CO₂CH₃)₅, MOC₂O₄, Mo₂(C₂O₄)₃, Mo(C₂O₄)₂, Mo₂(C₂O₄)₅, Mo₃(PO₄)₂, MoHPO₄, Mo(H₂PO₄)₂, Mo(CO₂H)₂, Mo(OR)₂, MoPO₄, Mo₂(HPO₄)₃, Mo(H₂PO₄)₃, Mo(CO₂H)₃, Mo(OR)₃, Mo₃(PO₄)₄, Mo(HPO₄)₂, Mo(H₂PO₄)₄, Mo(CO₂H)₄, Mo(OR)₄, Mo₃(PO₄)₅, Mo₂(HPO₄)₅, Mo(H₂PO₄)₅, Mo(CO₂H)₅, Mo(OR)₅, VCl, VCl₂, VCl₃, VCl₄, VCl₅, VBr, VBr₂, VBr₃, VBr₄, VBr₅, VI, VI₂, VI₃, VI₄, VI₅, VNO₃, V(NO₃)₂, V(NO₃)₃, V(NO₃)₄, V(NO₃)₅, V₂SO₄, VSO₄, V₂(SO₄)₃, V(SO₄)₄, VCO₂CH₃, V(CO₂CH₃)₂, V(CO₂CH₃)₃, V(CO₂CH₃)₄, V₂C₂O₄, VC₂O₄, V₂(O₂O₄)₃, V(C₂O₄)₄, V₃PO₄, V₂HPO₄, VH₂PO₄, VCO₂H, VOR, V₃(PO₄)₂, VHPO₄, V(H₂PO₄)₂, V(CO₂H)₂, V(OR)₂, VPO₄, V₂(HPO₄)₃, V(H₂PO₄)₃, V(CO₂H)₃, V(OR)₃, V₃(PO₄)₄, V(HPO₄)₂, V(H₂PO₄)₄, V(CO₂H)₄, V(OR)₄, V₃(PO₄)₅, V₂(HPO₄)₅, V(H₂PO₄)₅, V(CO₂H)₅, V(OR)₅, TaCl, TaCl₂, TaCl₃, TaCl₄, TaCl₅, TaBr, TaBr₂, TaBr₃, TaBr₄, TaBr₅, TaI, TaI₂, TaI₃, TaI₄, TaI₅, TaNO₃, Ta(NO₃)₂, Ta(NO₃)₃, Ta(NO₃)₄, Ta(NO₃)₅, Ta₂SO₄, TaSO₄, Ta₂(SO₄)₃, Ta(SO₄)₄, TaCO₂CH₃, Ta(CO₂CH₃)₂, Ta(CO₂CH₃)₃, Ta(CO₂CH₃)₄, Ta₂C₂O₄, TaC₂O₄, Ta₂(C₂O₄)₃, Ta(C₂O₄)₄, Ta₃PO₄, Ta₂HPO₄, TaH₂PO₄, TaCO₂H, TaOR, Ta₃(PO₄)₂, TaHPO₄, Ta(H₂PO₄)₂, Ta(CO₂H)₂, Ta(OR)₂, TaPO₄, Ta₂(HPO₄)₃, Ta(H₂PO₄)₃, Ta(CO₂H)₃, Ta(OR)₃, Ta₃(PO₄)₄, Ta(HPO₄)₂, Ta(H₂PO₄)₄, Ta(CO₂H)₄, Ta(OR)₄, Ta₃(PO₄)₅, Ta₂(HPO₄)₅, Ta(H₂PO₄)₅, Ta(CO₂H)₅, Ta(OR)₅, NbCl, NbCl₂, NbCl₃, NbCl₄, NbCl₅, NbBr, NbBr₂, NbBr₃, NbBr₄, NbBr₅, NbI, NbI₂, NbI₃, NbI₄, NbI₅, NbNO₃, Nb(NO₃)₂, Nb(NO₃)₃, Nb(NO₃)₄, Nb(NO₃)₅, Nb₂SO₄, NbSO₄, Nb₂(SO₄)₃, Nb(SO₄)₄, NbCO₂CH₃, Nb(CO₂CH₃)₂, Nb(CO₂CH₃)₃, Nb(CO₂CH₃)₄, Nb₂C₂O₄, NbC₂O₄, Nb₂(C₂O₄)₃, Nb(C₂O₄)₄, Nb₃PO₄, Nb₂HPO₄, NbH₂PO₄, NbCO₂H, NbOR, Nb₃(PO₄)₂, NbHPO₄, Nb(H₂PO₄)₂, Nb(CO₂H)₂, Nb(OR)₂, NbPO₄, Nb₂(HPO₄)₃, Nb(H₂PO₄)₃, Nb(CO₂H)₃, Nb(OR)₃, Nb₃(PO₄)₄, Nb(HPO₄)₂, Nb(H₂PO₄)₄, Nb(CO₂H)₄, Nb(OR)₄, Nb₃(PO₄)₅, Nb₂(HPO₄)₅, Nb(H₂PO₄)₅, Nb(CO₂H)₅, Nb(OR)₅, NdC₁₃, NdBr₃, NdI₃, Nd(NO₃)₃, Nd₂(SO₄)₃, Nd(CO₂CH₃)₃, Nd₂(C₂O₄)₃, NdPO₄, Nd₂(HPO₄)₃, Nd(H₂PO₄)₃, Nd(CO₂H)₃, Nd(OR)₃, EuCl₃, EuBr₃, EuI₃, Eu(NO₃)₃, Eu₂(SO₄)₃, Eu(CO₂CH₃)₃, Eu₂(C₂O₄)₃, NdPO₄, Nd₂(HPO₄)₃, Nd(H₂PO₄)₃, Nd(CO₂H)₃, Nd(OR)₃, PrC₁₃, PrBr₃, Prl₃, Pr(NO₃)₃, Pr₂(SO₄)₃, Pr(CO₂CH₃)₃, Pr₂(C₂O₄)₃, PrPO₄, Pr₂(HPO₄)₃, Pr(H₂PO₄)₃, Pr(CO₂H)₃, Pr(OR)₃, SmCl₃, SmBr₃, SmI₃, Sm(NO₃)₃, Sm₂(SO₄)₃, Sm(CO₂CH₃)₃, Sm₂(C₂O₄)₃, SmPO₄, Sm₂(HPO₄)₃, Sm(H₂PO₄)₃, Sm(CO₂H)₃, Sm(OR)₃, CeCl₃, CeBr₃, CeI₃, Ce(NO₃)₃, Ce₂(SO₄)₃, Ce(CO₂CH₃)₃, Ce₂(C₂O₄)₃ CePO₄, Ce₂(HPO₄)₃, Ce(H₂PO₄)₃, Ce(CO₂H)₃, Ce(OR)₃, or combinations thereof, wherein R is alkyl, alkenyl, alkynyl or aryl.

In more specific embodiments, the metal salt comprises MgCl₂, LaCl₃, ZrCl₄, WCl₄, MoCl₄, MnCl₂ MnCl₃, Mg(NO₃)₂, La(NO₃)₃, ZrOCl₂, Mn(NO₃)₂, Mn(NO₃)₃, ZrO(NO₃)₂, Zr(NO₃)₄, or combinations thereof.

In other embodiments, the metal salt comprises NdCl₃, NdBr₃, NdI₃, Nd(NO₃)₃, Nd₂(SO₄)₃, Nd(CO₂CH₃)₃, Nd₂(C₂O₄)₃, EuCl₃, EuBr₃, EuI₃, Eu(NO₃)₃, Eu₂(SO₄)₃, Eu(CO₂CH₃)₃, Eu₂(C₂O₄)₃, PrCl₃, PrBr₃, Prl₃, Pr(NO₃)₃, Pr₂(SO₄)₃, Pr(CO₂CH₃)₃, Pr₂(C₂O₄)₃ or combinations thereof.

In still other embodiments, the metal salt comprises Mg, Ca, Mg, W, La, Nd, Sm, Eu, W, Mn, Zr or mixtures thereof. The salt may be in the form of (oxy)chlorides, (oxy)nitrates or tungstates.

(c) Anion Precursor

The anions, or counter ions of the metal ions that nucleate on the template, are provided in the form of an anion precursor. The anion precursor dissociates in the solution phase and releases an anion. Thus, the anion precursor can be any stable soluble salts having the desired anion. For instance, bases such as alkali metal hydroxides (e.g., sodium hydroxide, lithium hydroxide, potassium hydroxides) and ammonium hydroxide are anion precursors that provide hydroxide ions for nucleation. Alkali metal carbonates (e.g., sodium carbonate, potassium carbonates) and ammonium carbonate are anion precursors that provide carbonates ions for nucleation.

In certain embodiments, the anion precursor comprises one or more metal hydroxide, metal carbonate, metal bicarbonate, metal sulfate, metal phosphate or metal oxalate. Preferably, the metal is an alkali or an alkaline earth metal. Thus, the anion precursor may comprise any one of alkali metal hydroxides, carbonates, bicarbonates, sulfates, phosphates or oxalate; or any one of alkaline earth metal hydroxides, carbonates, bicarbonates, sulfates, phosphates or oxalates.

In some specific embodiments, the one or more anion precursors comprise LiOH, NaOH, KOH, Sr(OH)₂, Ba(OH)₂, Na₂CO₃, K₂CO₃, NaHCO₃, KHCO₃ (NR₄)₂CO₃, and NR₄OH, wherein each R is independently selected from H, C₁-C₁₈ alkyl, C₁-C₁₈ alkenyl, C₁-C₁₈ alkynyl and C₁-C₁₈ aryl. Ammonium salts may provide certain advantages in that there is less possibility of introducing unwanted metal impurities. Accordingly, in a further embodiment, the anion precursor comprises ammonium hydroxide or ammonium carbonate.

The dimensions of the nanowires are comparable to those of the polymer templates, although they can have different aspect ratios as longer growth can be used to increase the diameter while the length will increase in size at a much slower rate. The spacing of monomers on the polymer surface controls the nucleation location and the catalytic nanowire size based on steric hindrance. The monomer identity can (or may) dictate the identity, size, shape and crystalline face of the catalytic nanowire being nucleated. To achieve the desired stochiometry between metal elements, support and dopants, polymers comprising multiple monomers specific for these discrete materials can be used. Alternatively, precursor salts for the materials can be combined in the reaction at the desired stochiometry

3. Core/Shell Structures

In certain embodiments, nanowires can be grown on a support nanowire that has no or a different catalytic property. FIG. 7 shows an exemplary process 600 for growing a core/shell nanowire structure. Similar to the process described in FIG. 7, a polymer solution is prepared (block 604), to which a first metal salt and a first anion precursor are sequentially added (blocks 610 and 620) in appropriate conditions to allow for the nucleation and growth of a nanowire (M1_(m1)X1_(n1)Z_(p1)) on the polymer (block 624). Thereafter, a second metal salt and a second anion precursor are sequentially added (blocks 630 and 634), under conditions to cause the nucleation and growth of a coating of M2_(m2)X2_(n2)Z_(p2) on the nanowire M1_(m1)X1_(n1)Z_(p1) (block 640). Following calcinations, nanowires of a core/shell structure M1_(x1)O_(y1)/M2_(x2)O_(y2) are formed, wherein x1, y1, x2 and y2 are each independently a number from 1 to 100, and p1 and p2 are each independently a number from 0 to 100 (block 644). A further step of impregnation (block 650) produces a nanowire comprising a dopant and comprising a core of M1_(x1)O_(y1) coated with a shell of M2_(x2)O_(y2). For ease of illustration, FIG. 7 depicts calcinations prior to doping; however, in certain embodiments doping may be performed prior to calcinations. In some embodiments, M1 is Mg, Al, Ga, Ca or Zr. In certain embodiments of the foregoing, M1 is Mn and M2 is Mg. In other embodiments, M1 is Mg and M2 is Mn. In other embodiments, M1 is La and M2 is Mg, Ca, Sr, Ba, Zr, Nd, Y, Yb, Eu, Sm or Ce. In other embodiments, M1 is Mg and M2 is La or Nd.

In other embodiments, M1_(x1)O_(y1) comprises La₂O₃ while in other embodiments M2_(x2)O_(y2) comprises La₂O₃. In other embodiments of the foregoing, M1_(x1)O_(y1) or M2_(x2)O_(y2) further comprises a dopant, wherein the dopant comprises Nd, Mn, Fe, Zr, Sr, Ba, Y or combinations thereof. Other specific combinations of core/shell nanowires are also envisioned within the scope of the present disclosure.

Thus, one embodiment provides a method for preparing metal oxide, metal oxy-hydroxide, metal oxycarbonate or metal carbonate nanowires in a core/shell structure, the method comprising:

(a) providing a solution that includes a plurality of polymer templates;

(b) introducing a first metal ion and a first anion to the solution under conditions and for a time sufficient to allow for nucleation and growth of a first nanowire (M1_(m1)X1_(n1)Z_(p1)) on the template; and

(c) introducing a second metal ion and optionally a second anion to the solution under conditions and for a time sufficient to allow for nucleation and growth of a second nanowire (M2_(m2)X2_(n2)Z_(p2)) on the first nanowire (M1_(m1)X1_(n1)Z_(p1));

(d) converting the first nanowire (M1_(m1)X1_(n1)Z_(p1)) and the second nanowire (M2_(m2)X2_(n2)Z_(p2)) to the respective metal oxide nanowires (M1_(x1)O_(y1)) and (M2_(x2)O_(y2)), the respective metal oxy-hydroxide nanowires (M1_(x1)O_(y1)OH_(z1)) and (M2_(x2)O_(y2)OH_(z2)) the respective metal oxycarbonate nanowires (M1_(x1)O_(y1)(CO₃)_(z1)) and (M2_(x2)O_(y2)(CO₃)_(z2)) or the respective metal carbonate nanowires (M1_(x1)(CO₃)_(y1)) and (M2_(x2)(CO₃)_(y2)),

wherein:

M1 and M2 are the same or different and independently selected from a metal element;

X1 and X2 are the same or different and independently hydroxides, carbonates, bicarbonates, phosphates, hydrogenphosphates, dihydrogenphosphates, sulfates, nitrates or oxalates;

Z is O;

n1, m1, n2, m2, x1, y1, z1, x2, y2 and z2 are each independently a number from 1 to 100; and

p1 and p2 are independently a number from 0 to 100.

In some embodiments, M1 and M2 are the same or different and independently selected from a metal element from any of Groups 2 through 7, lanthanides or actinides

In various embodiments, the polymer templates are are selected from PVP (polyvinlpyrrolidone), PVA (polyvinylalcohol), PEI (polyethyleneimine), PEG (polyethyleneglycol), polyether, polyesters, polyamides, dextran and other sugar polymers, functionalized hydrocarbon polymers, functionalized polystyrene, polylactic acid, polycaprolactone, polyglycolic acid, poly(ethylene glycol)-poly(propylene glycol)-poly(ethylene glycol) and copolymers and combinations thereof. In some embodiments, the polymer template is functionalized with at least one of amine, carboxylic acid, sulfate, alcohol, halogen or thiol groups. For example the polymer template may be a hydrocarbon or polystyrene polymer functionalized with at least one of amine, carboxylic acid, sulfate, alcohol, halogen or thiol groups.

In some embodiments, the nanowire is dried in an oven, while in other embodiments the nanowire is freeze dried or air dried. The drying method may have an effect on the final morphology, pore size, etc. of the resulting nanowire. Additionally, the solution comprising the polymer template may be in the form of a gel and the metal ions are impregnated therein. The gel may then be dried as described above. In some different embodiments, the polymer template is removed from the nanowire by heat treatment or other removal means.

In further embodiments, the respective metal ion is provided by adding one or more respective metal salts (as described herein) to the solution. In other embodiments, the respective anions are provided by adding one or more respective anion precursors to the solution. In various embodiments, the first metal ion and the first anion can be introduced to the solution simultaneously or sequentially in any order. Similarly, the second metal ion and optionally the second anion can be introduced to the solution simultaneously or sequentially in any order. The first and second nanowire are typically converted to a metal oxide, metal oxy-hydroxide, metal oxycarbonate or metal carbonate nanowire in a core/shell structure by calcination.

In yet another embodiment, the method further comprises doping the metal oxide nanowire in a core/shell structure with a dopant.

By varying the nucleation conditions, including the pH of the solution, relative ratio of metal salt precursors and the anion precursors, relative ratios of the precursors and the polymer of the synthetic mixture, stable nanowires of diverse compositions and surface properties can be prepared.

In certain embodiments, the core nanowire (the first nanowire) is not catalytically active or less so than the shell nanowire (the second nanowire), and the core nanowire serve as an intrinsic catalytic support for the more active shell nanowire. For example, ZrO₂ may not have high catalytic activity in an OCM reaction, whereas Sr²⁺ doped La₂O₃ does. A ZrO₂ core thus may serve as a support for the catalytic Sr²⁺ doped La₂O₃ shell.

In some embodiments, the present disclosure provides a nanowire comprising a core/shell structure and comprising a ratio of effective length to actual length of less than one. In other embodiments, the nanowires having a core/shell structure comprise a ratio of effective length to actual length equal to one.

4. Diversity

As noted above, in some embodiments, the disclosed template-directed synthesis provides nanowires having diverse compositions and/or morphologies. This method enables production of a library of nanowire catalysts with a new level of control over materials composition, materials surface and crystal structure. These nanowires prepared by polymer-templated methods take advantage of the large variation of different polymer structures and sizes, etc. to enable combinatorial synthesis of robust, active and selective inorganic catalytic polycrystalline nanowires. Modification of the various synthetic parameters permits simultaneous optimization of the nanowires' catalytic properties in a high-dimensional space.

In various embodiments, the synthetic parameters for nucleating and growing nanowires can be manipulated to create nanowires of diverse compositions and morphologies. Typical synthetic parameters include, without limitation, concentration ratios of metal ions and active functional groups on the polymer (e.g., various monomers); concentration ratios of metal and anions (e.g., hydroxide); incubation time of polymer and metal salt; incubation time of polymer and anion; concentration of polymer; sequence of adding anion and metal ions; pH; polymer composition and size; solution temperature in the incubation step and/or growth step; types of metal precursor salt; types of anion precursor; addition rate, number of additions; the time that lapses between the additions of the metal salt and anion precursor, including, e.g., simultaneous (zero lapse) or sequential additions followed by respective incubation times for the metal salt and the anion precursor.

Additional variable synthetic parameters include, growth time once both metal and anion are present in the solution; choice of solvents (although water is typically used, certain amounts of alcohol, such as methanol, ethanol and propanol, can be mixed with water); choice and the number of metal salts used (e.g., both LaCl₃ and La(NO₃)₃ can be used to provide La³⁺ ions); choice and the number of anion precursors used (e.g., both NaOH then LiOH can be used to provide the hydroxide); choice or the number of different polymers used; the presence or absence of a buffer solution; the different stages of the growing step (e.g., nanowires may be precipitated and cleaned and resuspended in a second solution and perform a second growth of the same material (thicker core) or different material to form a core/shell structure.

Thus, libraries of nanowires can be generated with diverse physical properties and characteristics such as: composition, e.g., basic metal oxides (M_(x)O_(y)), size, shape, surface morphology, exposed crystal faces/edge density, crystallinity, dispersion, and stoichiometry and nanowire template physical characteristics including length, width, porosity and pore density. High throughput, combinatorial screening methods are then applied to evaluate the catalytic performance characteristics of the nanowires (see, e.g., FIG. 2). Based on these results, lead target candidates are identified. From these lead targets, further rational modifications to the synthetic designs can be made to create nanowires that satisfy certain catalytic performance criteria. This results in further refinement of the nanowire design and material structure.

Catalytic Reactions

The present disclosure provides for the use of catalytic nanowires as catalysts in catalytic reactions and related methods. In some embodiments, the catalytic reaction is any of the reactions described herein. The morphology and composition of the catalytic nanowires is not limited, and the nanowires may be prepared by any method. For example the nanowires may have a bent morphology or a straight morphology and may have any molecular composition. In some embodiments, the nanowires have better catalytic properties than a corresponding bulk catalyst (i.e., a catalyst having the same chemical composition as the nanowire, but prepared from bulk material). In some embodiments, the nanowire having better catalytic properties than a corresponding bulk catalyst has a ratio of effective length to actual length equal to one. In other embodiments, the nanowire having better catalytic properties than a corresponding bulk catalyst has a ratio of effective length to actual length of less than one. In other embodiments, the nanowire having better catalytic properties than a corresponding bulk catalyst comprises one or more elements from Groups 1 through 7, lanthanides or actinides.

Nanowires may be useful in any number of reactions catalyzed by a heterogeneous catalyst. Examples of reactions wherein nanowires having catalytic activity may be employed are disclosed in Farrauto and Bartholomew, “Fundamentals of Industrial Catalytic Processes” Blackie Academic and Professional, first edition, 1997, which is hereby incorporated in its entirety. Other non-limiting examples of reactions wherein nanowires having catalytic activity may be employed include: the oxidative coupling of methane (OCM) to ethane and ethylene; oxidative dehydrogenation (ODH) of alkanes to the corresponding alkenes, for example oxidative dehydrogenation of ethane or propane to ethylene or propylene, respectively; selective oxidation of alkanes, alkenes, and alkynes; oxidation of CO, dry reforming of methane, selective oxidation of aromatics; Fischer-Tropsch, hydrocarbon cracking; combustion of hydrocarbons and the like. Reactions catalyzed by the disclosed nanowires are discussed in more detail below.

The nanowires are generally useful as catalysts in methods for converting a first carbon-containing compound (e.g., a hydrocarbon, CO or CO₂) to a second carbon-containing compound. In some embodiments the methods comprise contacting a nanowire, or material comprising the same, with a gas comprising a first carbon-containing compound and an oxidant to produce a carbon-containing compound. In some embodiments, the first carbon-containing compound is a hydrocarbon, CO, CO₂, methane, ethane, propane, hexane, cyclohexane, octane or combinations thereof. In other embodiments, the second carbon-containing compound is a hydrocarbon, CO, CO₂, ethane, ethylene, propane, propylene, hexane, hexene, cyclohexane, cyclohexene, bicyclohexane, octane, octene or hexadecane. In some embodiments, the oxidant is oxygen, ozone, nitrous oxide, nitric oxide, carbon dioxide, water or combinations thereof.

In other embodiments of the foregoing, the method for conversion of a first carbon-containing compound to a second carbon-containing compound is performed at a temperature below 100° C., below 200° C., below 300° C., below 400° C., below 500° C., below 600° C., below 700° C., below 800° C., below 900° C. or below 1000° C. In other embodiments, the method for conversion of a first carbon-containing compound to a second carbon-containing compound is performed at a pressure above 0.5 ATM, above 1 ATM, above 2 ATM, above 5 ATM, above 10 ATM, above 25 ATM or above 50 ATM.

The catalytic reactions described herein can be performed using standard laboratory equipment known to those of skill in the art, for example as described in U.S. Pat. No. 6,350,716, which is incorporated herein in its entirety.

As noted above, the nanowires disclosed herein have better catalytic activity than a corresponding bulk catalyst. In some embodiments, the selectivity, yield, conversion, or combinations thereof, of a reaction catalyzed by the nanowires is better than the selectivity, yield, conversion, or combinations thereof, of the same reaction catalyzed by a corresponding bulk catalyst under the same conditions. For example, in some embodiments, the nanowire possesses a catalytic activity such that conversion of reactant to product in a reaction catalyzed by the nanowire is greater than at least 1.1 times, greater than at least 1.25 times, greater than at least 1.5 times, greater than at least 2.0 times, greater than at least 3.0 times or greater than at least 4.0 times the conversion of reactant to product in the same reaction catalyzed by a catalyst prepared from bulk material having the same chemical composition as the nanowire.

In other embodiments, the nanowire possesses a catalytic activity such that selectivity for product in a reaction catalyzed by the nanowire is greater than at least 1.1 times, greater than at least 1.25 times, greater than at least 1.5 times, greater than at least 2.0 times, greater than at least 3.0 times, or greater than at least 4.0 times the selectivity for product in the same reaction under the same conditions but catalyzed by a catalyst prepared from bulk material having the same chemical composition as the nanowire.

In yet other embodiments, the nanowire possesses a catalytic activity such that yield of product in a reaction catalyzed by the nanowire is greater than at least 1.1 times, greater than at least 1.25 times, greater than at least 1.5 times, greater than at least 2.0 times, greater than at least 3.0 times, or greater than at least 4.0 times the yield of product in the same reaction under the same conditions but catalyzed by a catalyst prepared from bulk material having the same chemical composition as the nanowire.

In yet other embodiments, the nanowire possesses a catalytic activity such that activation temperature of a reaction catalyzed by the nanowire is at least 25° C. lower, at least 50° C. lower, at least 75° C. lower, or at least 100° C. lower than the temperature of the same reaction under the same conditions but catalyzed by a catalyst prepared from bulk material having the same chemical composition as the nanowire.

In certain reactions (e.g., OCM), production of unwanted oxides of carbon (e.g., CO and CO₂) is a problem that reduces overall yield of desired product and results in an environmental liability. Accordingly, in one embodiment the present disclosure addresses this problem and provides nanowires with a catalytic activity such that the selectivity for CO and/or CO₂ in a reaction catalyzed by the nanowires is less than the selectivity for CO and/or C002 in the same reaction under the same conditions but catalyzed by a corresponding bulk catalyst. Accordingly, in one embodiment, the present disclosure provides a nanowire which possesses a catalytic activity such that selectivity for CO_(x), wherein x is 1 or 2, in a reaction catalyzed by the nanowire is less than at least 0.9 times, less than at least 0.8 times, less than at least 0.5 times, less than at least 0.2 times or less than at least 0.1 times the selectivity for CO_(x) in the same reaction under the same conditions but catalyzed by a catalyst prepared from bulk material having the same chemical composition as the nanowire.

In some embodiments, the absolute selectivity, yield, conversion, or combinations thereof, of a reaction catalyzed by the nanowires disclosed herein is better than the absolute selectivity, yield, conversion, or combinations thereof, of the same reaction under the same conditions but catalyzed by a corresponding bulk catalyst. For example, in some embodiments the yield of product in a reaction catalyzed by the nanowires is greater than 20%, greater than 30%, greater than 50%, greater than 75%, or greater than 90%. In other embodiments, the selectivity for product in a reaction catalyzed by the nanowires is greater than 20%, greater than 30%, greater than 50%, greater than 75%, or greater than 90%. In other embodiments, the conversion of reactant to product in a reaction catalyzed by the nanowires is greater than 20%, greater than 30%, greater than 50%, greater than 75%, or greater than 90%.

In addition to the improved catalytic performance of the disclosed nanowires, the morphology of the nanowires is expected to provide for improved mixing properties for the nanowires compared to standard colloidal (e.g., bulk) catalyst materials. The improved mixing properties are expected to improve the performance of any number of catalytic reactions, for example, in the area of transformation of heavy hydrocarbons where transport and mixing phenomena are known to influence the catalytic activity. In other reactions, the shape of the nanowires is expected to provide for good blending, reduce settling, and provide for facile separation of any solid material.

In some other chemical reactions, the nanowires are useful for absorption and/or incorporation of a reactant used in chemical looping. For example, the nanowires find utility as NO_(x) traps, in unmixed combustion schemes, as oxygen storage materials, as CO₂ sorption materials (e.g., cyclic reforming with high H₂ output) and in schemes for conversion of water to H₂.

1. Oxidative Coupling of Methane (OCM)

As noted above, the present disclosure provides nanowires having catalytic activity and related approaches to nanowire design and preparation for improving the yield, selectivity and/or conversion of any number of catalyzed reactions, including the OCM reaction. As mentioned above, there exists a tremendous need for catalyst technology capable of addressing the conversion of methane into high value chemicals (e.g., ethylene and products prepared therefrom) using a direct route that does not go through syngas. Accomplishing this task will dramatically impact and redefine a non-petroleum based pathway for feedstock manufacturing and liquid fuel production yielding reductions in GHG emissions, as well as providing new fuel sources.

Ethylene has the largest carbon footprint compared to all industrial chemical products in part due to the large total volume consumed into a wide range of downstream important industrial products including plastics, surfactants and pharmaceuticals. In 2008, worldwide ethylene production exceeded 120 M metric tons while growing at a robust rate of 4% per year. The United States represents the largest single producer at 28% of the world capacity. Ethylene is primarily manufactured from high temperature cracking of naphtha (e.g., oil) or ethane that is separated from natural gas. The true measurement of the carbon footprint can be difficult as it depends on factors such as the feedstock and the allocation as several products are made and separated during the same process. However, some general estimates can be made based on published data.

Cracking consumes a significant portion (about 65%) of the total energy used in ethylene production and the remainder is for separations using low temperature distillation and compression. The total tons of CO₂ emission per ton of ethylene are estimated at between 0.9 to 1.2 from ethane cracking and 1 to 2 from naphtha cracking. Roughly, 60% of ethylene produced is from naphtha, 35% from ethane and 5% from others sources (Ren, T.; Patel, M. Res. Conserv. Recycl. 53:513, 2009). Therefore, based on median averages, an estimated amount of CO₂ emissions from the cracking process is 114M tons per year (based on 120M tons produced). Separations would then account for an additional 61M tons CO₂ per year.

Nanowires provide an alternative to the need for the energy intensive cracking step. Additionally, because of the high selectivity of the nanowires, downstream separations are dramatically simplified, as compared to cracking which yields a wide range of hydrocarbon products. The reaction is also exothermic so it can proceed via an autothermal process mechanism. Overall, it is estimated that up to a potential 75% reduction in CO₂ emission compared to conventional methods could be achieved. This would equate to a reduction of one billion tons of CO₂ over a ten-year period and would save over 1M barrels of oil per day.

The nanowires also permit converting ethylene into liquid fuels such as gasoline or diesel, given ethylene's high reactivity and numerous publications demonstrating high yield reactions, in the lab setting, from ethylene to gasoline and diesel. On a life cycle basis from well to wheel, recent analysis of methane to liquid (MTL) using F-T process derived gasoline and diesel fuels has shown an emission profile approximately 20% greater to that of petroleum based production (based on a worst case scenario) (Jaramillo, P., Griffin, M., Matthews, S., Env. Sci. Tech 42:7559, 2008). In the model, the CO₂ contribution from plant energy was a dominating factor at 60%. Thus, replacement of the cracking and F-T process would be expected to provide a notable reduction in net emissions, and could be produced at lower CO₂ emissions than petroleum based production.

Furthermore, a considerable portion of natural gas is found in regions that are remote from markets or pipelines. Most of this gas is flared, re-circulated back into oil reservoirs, or vented given its low economic value. The World Bank estimates flaring adds 400M metric tons of CO₂ to the atmosphere each year as well as contributing to methane emissions. The nanowires of this disclosure also provide economic and environmental incentive to stop flaring. Also, the conversion of methane to fuel has several environmental advantages over petroleum-derived fuel. Natural gas is the cleanest of all fossil fuels, and it does not contain a number of impurities such as mercury and other heavy metals found in oil. Additionally, contaminants including sulfur are also easily separated from the initial natural gas stream. The resulting fuels burn much cleaner with no measurable toxic pollutants and provide lower emissions than conventional diesel and gasoline in use today.

In view of its wide range of applications, the nanowires of this disclosure can be used to not only selectively activate alkanes, but also to activate other classes of inert unreactive bonds, such as C—F, C—Cl or C—O bonds. This has importance, for example, in the destruction of man-made environmental toxins such as CFCs, PCBs, dioxins and other pollutants. Accordingly, while the invention is described in greater detail below in the context of the OCM reaction and other the other reactions described herein, the nanowire catalysts are not in any way limited to this particular reaction.

The selective, catalytic oxidative coupling of methane to ethylene (i.e. the OCM reaction) is shown by the following reaction (1):

2CH₄+O₂→CH₂CH₂+2H₂O  (1)

This reaction is exothermic (Heat of Reaction −67 kcals/mole) and usually occurs at very high temperatures (>700° C.). During this reaction, it is believed that the methane (CH₄) is first oxidatively coupled into ethane (C₂H₆), and subsequently the ethane (C₂H₆) is oxidatively dehydrogenated into ethylene (C₂H₄). Because of the high temperatures used in the reaction, it has been suggested that the ethane is produced mainly by the coupling in the gas phase of the surface-generated methyl (CH₃) radicals. Reactive metal oxides (oxygen type ions) are apparently required for the activation of CH₄ to produce the CH₃ radicals. The yield of C₂H₄ and C₂H₆ is limited by further reactions in the gas phase and to some extent on the catalyst surface. A few of the possible reactions that occur during the oxidation of methane are shown below as reactions (2) through (8):

CH₄→CH₃ radical  (2)

CH₃ radical→C₂H₆  (3)

CH₃ radical+2.5O₂→CO₂+1.5H₂O  (4)

C₂H₆→C₂H₄+H₂  (5)

C₂H₆+0.5O₂→C₂H₄+H₂O  (6)

C₂H₄+3O₂→2CO₂+2H₂O  (7)

CH₃ radical+C_(x)H_(y)+O₂→Higher HC's−Oxidation/CO₂+H₂O  (8)

With conventional heterogeneous catalysts and reactor systems, the reported performance is generally limited to <25% CH₄ conversion at <80% combined C₂ selectivity, with the performance characteristics of high selectivity at low conversion, or the low selectivity at high conversion. In contrast, the nanowires of this disclosure are highly active and can optionally operate at a much lower temperature. In one embodiment, the nanowires disclosed herein enable efficient conversion of methane to ethylene in the OCM reaction at temperatures less than when the corresponding bulk material is used as a catalyst. For example, in one embodiment, the nanowires disclosed herein enable efficient conversion (i.e., high yield, conversion, and/or selectivity) of methane to ethylene at temperatures of less than 900° C., less than 800° C., less than 700° C., less than 600° C., or less than 500° C. In other embodiments, the use of staged oxygen addition, designed heat management, rapid quench and/or advanced separations may also be employed.

Accordingly, one embodiment of the present disclosure is a method for the preparation of ethan and/or ethylene, the method comprising converting methane to ethan and/or ethylene in the presence of a catalytic material, wherein the catalytic material comprises at least one catalytic nanowire as disclosed herein.

Accordingly, in one embodiment a stable, very active, high surface area, multifunctional nanowire catalyst is disclosed having active sites that are isolated and precisely engineered with the catalytically active metal centers/sites in the desired proximity (see, e.g., FIG. 1).

The exothermic heats of reaction (free energy) follow the order of reactions depicted above and, because of the proximity of the active sites, will mechanistically favor ethylene formation while minimizing complete oxidation reactions that form CO and CO₂. Representative nanowire compositions useful for the OCM reaction include, but are not limited to: highly basic oxides selected from the early members of the Lanthanide oxide series; Group 1 or 2 ions supported on basic oxides, such as Li/MgO, Ba/MgO and Sr/La₂O₃; and single or mixed transition metal oxides, such as VO_(x) and Re/Ru that may also contain Group 1 ions. Other nanowire compositions useful for the OCM reaction comprise any of the compositions disclosed herein, for example MgO, La₂O₃, Na₂WO₄, Mn₂O₃, Mn₃O₄, Mg₆MnO₈, Zr₂Mo₂O₈, NaMnO₄, Mn₂O₃/Na₂WO₄, Mn₃O₄/Na₂WO₄ or Na/MnO₄/MgO, Mn/WO₄, Nd₂O₃, Sm₂O₃, Eu₂O₃ or combinations thereof. Activating promoters (i.e., dopants), such as chlorides, nitrates and sulfates, or any of the dopants described above may also be employed.

As noted above, the presently disclosed nanowires comprise a catalytic performance better than corresponding bulk catalysts, for example in one embodiment the catalytic performance of the nanowires in the OCM reaction is better than the catalytic performance of a corresponding bulk catalyst. In this regard, various performance criteria may define the “catalytic performance” of the catalysts in the OCM (and other reactions). In one embodiment, catalytic performance is defined by C2 selectivity in the OCM reaction, and the C2 selectivity of the nanowires in the OCM reaction is >5%, >10%, >15%, >20%, >25%, >30%, >35%, >40%, >45%, >50%, >55%, >60%, >65%, >70%, >75% or >80%.

Other important performance parameters used to measure the nanowires' catalytic performance in the OCM reaction are selected from single pass methane conversion percentage (i.e., the percent of methane converted on a single pass over the catalyst or catalytic bed, etc.), reaction inlet gas temperature, reaction operating temperature, total reaction pressure, methane partial pressure, gas-hour space velocity (GHSV), O₂ source, catalyst stability and ethylene to ethane ratio. In certain embodiments, improved catalytic performance is defined in terms of the nanowires' improved performance (relative to a corresponding bulk catalyst) with respect to at least one of the foregoing performance parameters.

The reaction inlet gas temperature in an OCM reaction catalyzed by the disclosed nanowires can generally be maintained at a lower temperature, while maintaining better performance characteristics (e.g., conversion, C2 yield, C2 selectivity and the like) compared to the same reaction catalyzed by a corresponding bulk catalyst under the same reaction conditions. In certain embodiments, the inlet gas temperature in an OCM reaction catalyzed by the disclosed nanowires is <700° C., <675° C., <650° C., <625° C., <600° C., <593° C., <580° C., <570° C., <560° C., <550° C., <540° C., <530° C., <520° C., <510° C., <500° C., <490° C., <480° C. or even <470° C.

The reaction operating temperature in an OCM reaction catalyzed by the disclosed nanowires can generally be maintained at a lower temperature, while maintaining better performance characteristics compared to the same reaction catalyzed by a corresponding bulk catalyst under the same reaction conditions. In certain embodiments, the reaction operating temperature in an OCM reaction catalyzed by the disclosed nanowires is <700° C., <675° C., <650° C., <625° C., <600° C., <593° C., <580° C., <570° C., <560° C., <550° C., <540° C., <530° C., <520° C., <510° C., <500° C., <490° C., <480° C., <470° C.

The single pass methane conversion in an OCM reaction catalyzed by the nanowires is also generally better compared to the single pass methane conversion in the same reaction catalyzed by a corresponding bulk catalyst under the same reaction conditions. For single pass methane conversion it is preferably >5%, >10%, >15%, >20%, >25%, >30%, >35%, >40%, >45%, >50%, >55%, >60%, >65%, >70%, >75%, >80%.

In certain embodiments, the total reaction pressure in an OCM reaction catalyzed by the nanowires is >1 atm, >1.1 atm, >1.2 atm, >1.3 atm, >1.4 atm, >1.5 atm, >1.6 atm, >1.7 atm, >1.8 atm, >1.9 atm, >2 atm, >2.1 atm, >2.1 atm, >2.2 atm, >2.3 atm, >2.4 atm, >2.5 atm, >2.6 atm, >2.7 atm, >2.8 atm, >2.9 atm, >3.0 atm, >3.5 atm, >4.0 atm, >4.5 atm, >5.0 atm, >5.5 atm, >6.0 atm, >6.5 atm, >7.0 atm, >7.5 atm, >8.0 atm, >8.5 atm, >9.0 atm, >10.0 atm, >11.0 atm, >12.0 atm, >13.0 atm, >14.0 atm, >15.0 atm, >16.0 atm, >17.0 atm, >18.0 atm, >19.0 atm or >20.0 atm.

In some embodiments, the methane partial pressure in an OCM reaction catalyzed by the nanowires is >0.3 atm, >0.4 atm, >0.5 atm, >0.6 atm, >0.7 atm, >0.8 atm, >0.9 atm, >1 atm, >1.1 atm, >1.2 atm, >1.3 atm, >1.4 atm, >1.5 atm, >1.6 atm, >1.7 atm, >1.8 atm, >1.9 atm, >2.0 atm, >2.1 atm, >2.2 atm, >2.3 atm, >2.4 atm, >2.5 atm, >2.6 atm, >2.7 atm, >2.8 atm, >2.9 atm, >3.0 atm, >3.5 atm, >4.0 atm, >4.5 atm, >5.0 atm, >5.5 atm, >6.0 atm, >6.5 atm, >7.0 atm, >7.5 atm, >8.0 atm, >8.5 atm, >9.0 atm, >10.0 atm, >11.0 atm, >12.0 atm, >13.0 atm, >14.0 atm, >15.0 atm, >16.0 atm, >17.0 atm, >18.0 atm, >19.0 atm or >20.0 atm.

In some embodiments, the GSHV in an OCM reaction catalyzed by the nanowires is >20,000/hr, >50,000/hr, >75,000/hr, >100,000/hr, >120,000/hr, >130,000/hr, >150,000/hr, >200,000/hr, >250,000/hr, >300,000/hr, >350,000/hr, >400,000/hr, >450,000/hr, >500,000/hr, >750,000/hr, >1,000,000/hr, >2,000,000/hr, >3,000,000/hr, >4,000,000/hr.

In contrast to other OCM reactions, the present inventors have discovered that OCM reactions catalyzed by the disclosed nanowires can be performed (and still maintain high C2 yield, C2 selectivity, conversion, etc.) using O₂ sources other than pure O₂. For example, in some embodiments the O₂ source in an OCM reaction catalyzed by the disclosed nanowires is air, oxygen enriched air, pure oxygen, oxygen diluted with nitrogen (or another inert gas) or oxygen diluted with CO₂. In certain embodiments, the O₂ source is O₂ diluted by >99%, >98%, >97%, >96%, >95%, >94%, >93%, >92%, >91%, >90%, >85%, >80%, >75%, >70%, >65%, >60%, >55%, >50%, >45%, >40%, >35%, >30%, >25%, >20%, >15%, >10%, >9%, >8%, >7%, >6%, >5%, >4%, >3%, >2% or >1% with CO₂ or an inert gas, for example nitrogen.

The disclosed nanowires are also very stable under conditions required to perform any number of catalytic reactions, for example the OCM reaction. The stability of the nanowires is defined as the length of time a catalyst will maintain its catalytic performance without a significant decrease in performance (e.g., a decrease >20%, >15%, >10%, >5%, or greater than 1% in C2 yield, C2 selectivity or conversion, etc.). In some embodiments, the nanowires have stability under conditions required for the OCM reaction of >1 hr, >5 hrs, >10 hrs, >20 hrs, >50 hrs, >80 hrs, >90 hrs, >100 hrs, >150 hrs, >200 hrs, >250 hrs, >300 hrs, >350 hrs, >400 hrs, >450 hrs, >500 hrs, >550 hrs, >600 hrs, >650 hrs, >700 hrs, >750 hrs, >800 hrs, >850 hrs, >900 hrs, >950 hrs, >1,000 hrs, >2,000 hrs, >3,000 hrs, >4,000 hrs, >5,000 hrs, >6,000 hrs, >7,000 hrs, >8,000 hrs, >9,000 hrs, >10,000 hrs, >11,000 hrs, >12,000 hrs, >13,000 hrs, >14,000 hrs, >15,000 hrs, >16,000 hrs, >17,000 hrs, >18,000 hrs, >19,000 hrs, >20,000 hrs, >1 yrs, >2 yrs, >3 yrs, >4 yrs or >5 yrs.

In some embodiments, the ratio of ethylene to ethane in an OCM reaction catalyzed by the nanowires is better than the ratio of ethylene to ethane in an OCM reaction catalyzed by a corresponding bulk catalyst under the same conditions. In some embodiments, the ratio of ethylene to ethane in an OCM reaction catalyzed by the nanowires is >0.3, >0.4, >0.5, >0.6, >0.7, >0.8, >0.9, >1, >1.1, >1.2, >1.3, >1.4, >1.5, >1.6, >1.7, >1.8, >1.9, >2.0, >2.1, >2.2, >2.3, >2.4, >2.5, >2.6, >2.7, >2.8, >2.9, >3.0, >3.5, >4.0, >4.5, >5.0, >5.5, >6.0, >6.5, >7.0, >7.5, >8.0, >8.5, >9.0, >9.5, >10.0.

As noted above, the OCM reaction employing known bulk catalysts suffers from poor yield, selectivity, or conversion. In contrast to a corresponding bulk catalyst, Applicants have found that certain nanowires, for example the exemplary nanowires disclosed herein, posses a catalytic activity in the OCM reaction such that the yield, selectivity, and/or conversion is better than when the OCM reaction is catalyzed by a corresponding bulk catalyst. In one embodiment, the disclosure provides a nanowire having a catalytic activity such that the conversion of methane to ethylene in the oxidative coupling of methane reaction is greater than at least 1.1 times, 1.25 times, 1.50 times, 2.0 times, 3.0 times, or 4.0 times the conversion of methane to ethylene compared to the same reaction under the same conditions but performed with a catalyst prepared from bulk material having the same chemical composition as the nanowire. In other embodiments, the conversion of methane to ethylene in an OCM reaction catalyzed by the nanowire is greater than 10%, greater than 20%, greater than 30%, greater than 50%, greater than 75%, or greater than 90%.

In another embodiment, the disclosure provides a nanowire having a catalytic activity such that the yield of ethylene in the oxidative coupling of methane reaction is greater than at least 1.1 times, 1.25 times, 1.50 times, 2.0 times, 3.0 times, or 4.0 times the yield of ethylene compared to the same reaction under the same conditions but performed with a catalyst prepared from bulk material having the same chemical composition as the nanowire. In some embodiments the yield of ethylene in an OCM reaction catalyzed by the nanowire is greater than 10%, greater than 20%, greater than 30%, greater than 50%, greater than 75%, or greater than 90%.

As noted above, the OCM reaction employing known bulk catalysts suffers from poor yield, selectivity, or conversion. In contrast to a corresponding bulk catalyst, Applicants have found that certain nanowires, for example the exemplary nanowires disclosed herein, posses a catalytic activity in the OCM reaction such that the yield, selectivity, and/or conversion is better than when the OCM reaction is catalyzed by a corresponding bulk catalyst. In one embodiment, the disclosure provides a nanowire having a catalytic activity such that the conversion of methane in the oxidative coupling of methane reaction is greater than at least 1.1 times, 1.25 times, 1.50 times, 2.0 times, 3.0 times, or 4.0 times the conversion of methane compared to the same reaction under the same conditions but performed with a catalyst prepared from bulk material having the same chemical composition as the nanowire. In other embodiments, the conversion of methane in an OCM reaction catalyzed by the nanowire is greater than 10%, greater than 20%, greater than 30%, greater than 50%, greater than 75%, or greater than 90%.

In another embodiment, the disclosure provides a nanowire having a catalytic activity such that the C2 yield in the oxidative coupling of methane reaction is greater than at least 1.1 times, 1.25 times, 1.50 times, 2.0 times, 3.0 times, or 4.0 times the C2 yield compared to the same reaction under the same conditions but performed with a catalyst prepared from bulk material having the same chemical composition as the nanowire. In some embodiments the C2 yield in an OCM reaction catalyzed by the nanowire is greater than 10%, greater than 20%, greater than 30%, greater than 50%, greater than 75%, or greater than 90%.

In another embodiment, the disclosure provides a nanowire having a catalytic activity in the OCM reaction such that the nanowire has the same catalytic activity (i.e., same selectivity, conversion or yield), but at a lower temperature, compared a catalyst prepared from bulk material having the same chemical composition as the nanowire. In some embodiments the catalytic activity of the nanowires in the OCM reaction is the same as the catalytic activity of a catalyst prepared from bulk material having the same chemical composition as the nanowire, but at a temperature of at least 20° C. less. In some embodiments the catalytic activity of the nanowires in the OCM reaction is the same as the catalytic activity of a catalyst prepared from bulk material having the same chemical composition as the nanowire, but at a temperature of at least 50° C. less. In some embodiments the catalytic activity of the nanowires in the OCM reaction is the same as the catalytic activity of a catalyst prepared from bulk material having the same chemical composition as the nanowire, but at a temperature of at least 100° C. less. In some embodiments the catalytic activity of the nanowires in the OCM reaction is the same as the catalytic activity of a catalyst prepared from bulk material having the same chemical composition as the nanowire, but at a temperature of at least 200° C. less.

In another embodiment, the disclosure provides a nanowire having a catalytic activity such that the selectivity for CO or CO₂ in the oxidative coupling of methane reaction is less than at least 0.9 times, 0.8 times, 0.5 times, 0.2 times, or 0.1 times the selectivity for CO or CO₂ compared to the same reaction under the same conditions but performed with a catalyst prepared from bulk material having the same chemical composition as the nanowire.

In some other embodiments, a method for converting methane into ethylene comprising use of catalyst mixture comprising two or more catalysts is provided. For example, the catalyst mixture may be a mixture of a catalyst having good OCM activity and a catalyst having good ODH activity. Such catalyst mixture are described in more detail above.

Typically, the OCM reaction is run in a mixture of oxygen and nitrogen or other inert gas. Such gasses are expensive and increase the overall production costs associated with preparation of ethylene or ethane from methane. However, the present inventors have now discovered that such expensive gases are not required and high yield, conversion, selectivity, etc. can be obtained when air is used as the gas mixture instead of pre-packaged and purified sources of oxygen and other gases. Accordingly, in one embodiment the disclosure provides a method for performing the OCM reaction in air.

In addition to air or O₂ gas, the presently disclosed nanowires and associated methods provide for use of other sources of oxygen in the OCM reaction. In this respect, an alternate source of oxygen such a CO₂, H₂O, SO₂ or SO₃ may be used either in place of, or in addition to, air or oxygen as the oxygen source. Such methods have the potential to increase the efficiency of the OCM reaction, for example by consuming a reaction byproduct (e.g., CO₂ or H₂O) and controlling the OCM exotherm as described below.

As noted above, in the OCM reaction, methane is oxidatively converted to methyl radicals, which are then coupled to form ethane, which is subsequently oxidized to ethylene. In traditional OCM reactions, the oxidation agent for both the methyl radical formation and the ethane oxidation to ethylene is oxygen. In order to minimize full oxidation of methane or ethane to carbon dioxide, i.e. maximize C2 selectivity, the methane to oxygen ratio is generally kept at 4 (i.e. full conversion of methane into methyl radicals) or above. As a result, the OCM reaction is typically oxygen limited and thus the oxygen concentration in the effluent is zero.

Accordingly, in one embodiment the present disclosure provides a method for increasing the methane conversion and increasing, or in some embodiments, not reducing, the C2 selectivity in an OCM reaction. The disclosed methods include adding to a traditional OCM catalyst another OCM catalyst that uses an oxygen source other than molecular oxygen. In some embodiments, the alternate oxygen source is CO₂, H₂O, SO₂, SO₃ or combinations thereof. For example in some embodiments, the alternate oxygen source is CO₂. In other embodiments the alternate oxygen source is H₂O.

Because C2 selectivity is typically between 50% and 80% in the OCM reaction, OCM typically produces significant amounts of CO₂ as a byproduct (CO₂ selectivity can typically range from 20-50%). Additionally, H₂O is produced in copious amounts, regardless of the C2 selectivity. Therefore both CO₂ and H₂O would are attractive oxygen sources for OCM in an O₂ depleted environment.

Accordingly, one embodiment of the present disclosure provides a catalyst (and related methods for use thereof) which is catalytic in the OCM reaction and which uses CO₂, H₂O, SO₂, SO₃ or another alternative oxygen source or combinations thereof as a source of oxygen. Other embodiments, provide a catalytic material comprising two or more catalysts, wherein the catalytic material comprises at least one catalyst which is catalytic in the OCM reaction and uses O₂ for at least one oxygen source and at least one catalysts which is catalytic in the OCM reaction and uses at least of CO₂, H₂O, SO₂, SO₃, NO, NO₂, NO₃ or another alternative oxygen source. Methods for performing the OCM reaction with such catalytic materials are also provided. Such catalysts comprise any of the compositions disclosed herein and are effective as catalysts in an OCM reaction using an alternative oxygen source at temperatures of 900° C. or lower, 850° C. or lower, 800° C. or lower, 750° C. or lower, 700° C. or lower or even 650° C. or lower. In some embodiments of the above, the catalyst is a nanowire catalyst.

Examples of OCM catalysts that use CO₂ or other oxygen sources rather than O₂ include, but are not limited to, catalysts comprising La₂O₃/ZnO, CeO₂/ZnO, CaO/ZnO, CaO/CeO₂, CaO/Cr₂O₃, CaO/MnO₂, SrO/ZnO, SrO/CeO₂, SrO/Cr₂O₃, SrO/MnO₂, SrCO₃/MnO₂, BaO/ZnO, BaO/CeO₂, BaO/Cr₂O₃, BaO/MnO₂, CaO/MnO/CeO₂, Na₂WO₄/Mn/SiO₂, Pr₂O₃, Tb₂O₃.

Some embodiments provide a method for performing OCM, wherein a mixture of an OCM catalyst which use O₂ as an oxygen source (referred to herein as an O₂-OCM catalyst) and an OCM catalyst which use CO₂ as an oxygen source (referred to herein as a CO₂-OCM catalyst) is employed as the catalytic material, for example in a catalyst bed. Such methods have certain advantages. For example, the CO₂-OCM reaction is endothermic and the O₂-OCM reaction is exothermic, and thus if the right mixture and/or arrangement of CO₂-OCM and O₂-OCM catalysts is used, the methods are particularly useful for controlling the exotherm of the OCM reaction. In some embodiments, the catalyst bed comprises a mixture of O₂-OCM catalyst and CO₂-OCM catalysts. The mixture may be in a ratio of 1:99 to 99:1. The two catalysts work synergistically as the O₂-OCM catalyst supplies the CO₂-OCM catalyst with the necessary carbon dioxide and the endothermic nature of the C₂-OCM reaction serves to control the exotherm of the overall reaction. Alternatively, the CO₂ source may be external to the reaction (e.g., fed in from a CO₂ tank, or other source) and/or the heat required for the CO₂-OCM reaction is supplied from an external source (e.g., heating the reactor).

Since the gas composition will tend to become enriched in CO₂ as it flows through the catalyst bed (i.e., as the OCM reaction proceeds, more CO₂ is produced), some embodiments of the present invention provide an OCM method wherein the catalyst bed comprises a gradient of catalysts which changes from a high concentration of O₂-OCM catalysts at the front of the bed to a high concentration of CO₂-OCM catalysts at the end of the catalyst bed.

The O₂-OCM catalyst and CO₂ OCM catalyst may have the same or different compositions. For example, in some embodiments the O₂-OCM catalyst and CO₂-OCM catalyst have the same composition but different morphologies (e.g., nanowire, bent nanowire, bulk, etc.). In other embodiments the O₂-OCM and the CO₂-OCM catalyst have different compositions.

Furthermore, CO₂-OCM catalysts will typically have higher selectivity, but lower yields than an O₂-OCM catalyst. Accordingly, in one embodiment the methods comprise use of a mixture of an O₂-OCM catalyst and a CO₂-OCM catalyst and performing the reaction in O₂ deprived environment so that the CO₂-OCM reaction is favored and the selectivity is increased. Under appropriate conditions the yield and selectivity of the OCM reaction can thus be optimized.

In some other embodiments, the catalyst bed comprises a mixture of one or more low temperature O₂-OCM catalyst (i.e., a catalyst active at low temperatures, for example less than 700° C.) and one or more high temperature CO₂-OCM catalyst (i.e., a catalyst active at high temperatures, for example 800° C. or higher). Here, the required high temperature for the CO₂-OCM may be provided by the hotspots produced by the O₂-OCM catalyst. In such a scenario, the mixture may be sufficiently coarse such that the hotspots are not being excessively cooled down by excessive dilution effect.

In other embodiments, the catalyst bed comprises alternating layers of O₂-OCM and CO₂-OCM catalysts. The catalyst layer stack may begin with a layer of O₂-OCM catalyst, so that it can supply the next layer (e.g., a CO₂-OCM layer) with the necessary CO₂. The O₂-OCM layer thickness may be optimized to be the smallest at which O₂ conversion is 100% and thus the CH₄ conversion of the layer is maximized. The catalyst bed may comprise any number of catalyst layers, for example the overall number of layers may be optimized to maximize the overall CH₄ conversion and C2 selectivity.

In some embodiments, the catalyst bed comprises alternating layers of low temperature O₂-OCM catalysts and high temperature CO₂-OCM catalysts. Since the CO₂-OCM reaction is endothermic, the layers of CO₂-OCM catalyst may be sufficiently thin such that in can be “warmed up” by the hotspots of the O₂-OCM layers. The endothermic nature of the CO₂-OCM reaction can be advantageous for the overall thermal management of an OCM reactor. In some embodiments, the CO₂-OCM catalyst layers act as “internal” cooling for the O₂-OCM layers, thus simplifying the requirements for the cooling, for example in a tubular reactor. Therefore, an interesting cycle takes place with the endothermic reaction providing the necessary heat for the endothermic reaction and the endothermic reaction providing the necessary cooling for the exothermic reaction.

Accordingly, one embodiment of the present invention is a method for the oxidative coupling of methane, wherein the method comprises conversion of methane to ethane and/or ethylene in the presence of a catalytic material, and wherein the catalytic material comprises a bed of alternating layers of O₂-OCM catalysts and CO₂-OCM catalysts. In other embodiments the bed comprises a mixture (i.e., not alternating layers) of O₂-OCM catalysts and CO₂-OCM catalysts.

In other embodiments, the OCM methods include use of a jacketed reactor with the exothermic O₂-OCM reaction in the core and the endothermic CO₂-OCM reaction in the mantel. In other embodiments, the unused CO₂ can be recycled and reinjected into the reactor, optionally with the recycled CH₄. Additional CO₂ can also be injected to increase the overall methane conversion and help reduce greenhouse gases.

In other embodiments, the reactor comprises alternating stages of O₂-OCM catalyst beds and CO₂-OCM catalyst beds. The CO₂ necessary for the CO₂-OCM stages is provided by the O₂-OCM stage upstream. Additional CO₂ may also be injected. The O₂ necessary for the subsequent O₂-OCM stages is injected downstream from the CO₂-OCM stages. The CO₂-OCM stages may provide the necessary cooling for the O₂-OCM stages. Alternatively, separate cooling may be provided. Likewise, if necessary the inlet gas of the CO₂-OCM stages can be additionally heated, the CO₂-OCM bed can be heated or both.

In related embodiments, the CO₂ naturally occurring in natural gas is not removed prior to performing the OCM, alternatively CO₂ is added to the feed with the recycled methane. Instead the CO₂ containing natural gas is used as a feedstock for CO₂-OCM, thus potentially saving a separation step. The amount of naturally occurring CO₂ in natural gas depends on the well and the methods can be adjusted accordingly depending on the source of the natural gas.

The foregoing methods can be generalized as a method to control the temperature of very exothermic reactions by coupling them with an endothermic reaction that uses the same feedstock (or byproducts of the exothermic reaction) to make the same product (or a related product). This concept can be reversed, i.e. providing heat to an endothermic reaction by coupling it with an exothermic reaction. This will also allow a higher per pass yield in the OCM reactor.

For purpose of simplicity, the above description relating to the use of O₂-OCM and CO₂-OCM catalysts was described in reference to the oxidative coupling of methane (OCM); however, the same concept is applicable to other catalytic reactions including but not limited to: oxidative dehydrogenation (ODH) of alkanes to their corresponding alkenes, selective oxidation of alkanes and alkenes and alkynes, etc. For example, in a related embodiment, a catalyst capable of using an alternative oxygen source (e.g., CO₂, H₂O, SO₂, SO₃ or combinations thereof) to catalyze the oxidative dehydrogenation of ethane is provided. Such catalysts, and uses thereof are described in more detail below.

Furthermore, the above methods are applicable for creating novel catalysts by blending catalysts that use different reactants for the same catalytic reactions, for example different oxidants for an oxidation reaction and at least one oxidant is a byproduct of one of the catalytic reactions. In addition, the methods can also be generalized for internal temperature control of reactors by blending catalysts that catalyze reactions that share the same or similar products but are exothermic and endothermic, respectively. These two concepts can also be coupled together.

2. Oxidative Dehydrogenation

Worldwide demand for alkenes, especially ethylene and propylene, is high. The main sources for alkenes include steam cracking, fluid-catalytic-cracking and catalytic dehydrogenation. The current industrial processes for producing alkenes, including ethylene and propylene, suffer from some of the same disadvantages described above for the OCM reaction. Accordingly, a process for the preparation of alkenes, which is more energy efficient and has higher yield, selectivity, and conversion than current processes is needed. Applicants have now found that nanowires, for example the exemplary nanowires disclosed herein, fulfill this need and provide related advantages.

In one embodiment, the disclosed nanowires are useful as catalysts for the oxidative dehydrogenation (ODH) of hydrocarbons (e.g. alkanes, alkenes, and alkynes). For example, in one embodiment the nanowires are useful as catalysts in an ODH reaction for the conversion of ethane or propane to ethylene or propylene, respectively. Reaction scheme (9) depicts the oxidative dehydrogenation of hydrocarbons:

C_(x)H_(y)+½O₂→C_(x)H_(y-2)+H₂O  (9)

Representative catalysts useful for the ODH reaction include, but are not limited to nanowires comprising Zr, V, Mo, Ba, Nd, Ce, Ti, Mg, Nb, La, Sr, Sm, Cr, W, Y or Ca or oxides or combinations thereof. Activating promoters (i.e. dopants) comprising P, K, Ca, Ni, Cr, Nb, Mg, Au, Zn, or Mo, or combinations thereof, may also be employed.

As noted above, improvements to the yield, selectivity, and/or conversion in the ODH reaction employing bulk catalysts are needed. Accordingly, in one embodiment, the present disclosure provides a nanowire which posses a catalytic activity in the ODH reaction such that the yield, selectivity, and/or conversion is better than when the ODH reaction is catalyzed by a corresponding bulk catalyst. In one embodiment, the disclosure provides a nanowire having a catalytic activity such that the conversion of hydrocarbon to alkene in the ODH reaction is greater than at least 1.1 times, 1.25 times, 1.50 times, 2.0 times, 3.0 times, or 4.0 times the conversion of alkane to alkene compared to the same reaction under the same conditions but performed with a catalyst prepared from bulk material having the same chemical composition as the nanowire. In other embodiments, the conversion of hydrocarbon to alkene in an ODH reaction catalyzed by the nanowire is greater than 10%, greater than 20%, greater than 30%, greater than 50%, greater than 75%, or greater than 90%.

In another embodiment, the disclosure provides a nanowire having a catalytic activity such that the yield of alkene in an ODH reaction is greater than at least 1.1 times, 1.25 times, 1.50 times, 2.0 times, 3.0 times, or 4.0 times the yield of alkenes compared to the same reaction under the same conditions but performed with a catalyst prepared from bulk material having the same chemical composition as the nanowire. In some embodiments the yield of alkene in an ODH reaction catalyzed by the nanowire is greater than 10%, greater than 20%, greater than 30%, greater than 50%, greater than 75%, or greater than 90%.

In another embodiment, the disclosure provides a nanowire having a catalytic activity in the ODH reaction such that the nanowire has the same catalytic activity, but at a lower temperature, compared a catalyst prepared from bulk material having the same chemical composition as the nanowire. In some embodiments the catalytic activity of the nanowires in the ODH reaction is the same or better than the catalytic activity of a catalyst prepared from bulk material having the same chemical composition as the nanowire, but at a temperature of at least 20° C. less. In some embodiments the catalytic activity of the nanowires in the ODH reaction is the same or better than the catalytic activity of a catalyst prepared from bulk material having the same chemical composition as the nanowire, but at a temperature of at least 50° C. less. In some embodiments the catalytic activity of the nanowires in the ODH reaction is the same or better than the catalytic activity of a catalyst prepared from bulk material having the same chemical composition as the nanowire, but at a temperature of at least 100° C. less. In some embodiments the catalytic activity of the nanowires in the ODH reaction is the same or better than the catalytic activity of a catalyst prepared from bulk material having the same chemical composition as the nanowire, but at a temperature of at least 200° C. less.

In another embodiment, the disclosure provides a nanowire having a catalytic activity such that the selectivity for alkenes in an ODH reaction is greater than at least 1.1 times, 1.25 times, 1.50 times, 2.0 times, 3.0 times, or 4.0 times the selectivity for alkenes compared to the same reaction under the same conditions but performed with a catalyst prepared from bulk material having the same chemical composition as the nanowire. In other embodiments, the selectivity for alkenes in an ODH reaction catalyzed by the nanowire is greater than 50%, greater than 60%, greater than 70%, greater than 80%, greater than 90%, or greater than 95%.

In another embodiment, the disclosure provides a nanowire having a catalytic activity such that the selectivity for CO or CO₂ in an ODH reaction is less than at least 0.9 times, 0.8 times, 0.5 times, 0.2 times, or 0.1 times the selectivity for CO or CO₂ compared to the same reaction under the same conditions but performed with a catalyst prepared from bulk material having the same chemical composition as the nanowire.

In one embodiment, the nanowires disclosed herein enable efficient conversion of hydrocarbon to alkene in the ODH reaction at temperatures less than when the corresponding bulk material is used as a catalyst. For example, in one embodiment, the nanowires disclosed herein enable efficient conversion (i.e. high yield, conversion, and/or selectivity) of hydrocarbon to alkene at temperatures of less than 800° C., less than 700° C., less than 600° C., less than 500° C., less than 400° C., or less than 300° C.

The stability of the nanowires is defined as the length of time a catalyst will maintain its catalytic performance without a significant decrease in performance (e.g., a decrease >20%, >15%, >10%, >5%, or greater than 1% in ODH activity or alkene selectivity, etc.). In some embodiments, the nanowires have stability under conditions required for the ODH reaction of >1 hr, >5 hrs, >10 hrs, >20 hrs, >50 hrs, >80 hrs, >90 hrs, >100 hrs, >150 hrs, >200 hrs, >250 hrs, >300 hrs, >350 hrs, >400 hrs, >450 hrs, >500 hrs, >550 hrs, >600 hrs, >650 hrs, >700 hrs, >750 hrs, >800 hrs, >850 hrs, >900 hrs, >950 hrs, >1,000 hrs, >2,000 hrs, >3,000 hrs, >4,000 hrs, >5,000 hrs, >6,000 hrs, >7,000 hrs, >8,000 hrs, >9,000 hrs, >10,000 hrs, >11,000 hrs, >12,000 hrs, >13,000 hrs, >14,000 hrs, >15,000 hrs, >16,000 hrs, >17,000 hrs, >18,000 hrs, >19,000 hrs, >20,000 hrs, >1 yrs, >2 yrs, >3 yrs, >4 yrs or >5 yrs.

As noted above, one embodiment of the present disclosure is directed to a catalyst capable of using an alternative oxygen source (e.g., CO₂, H₂O, SO₂, SO₃ or combinations thereof) to catalyze the oxidative dehydrogenation of ethane is provided. For example, the ODH reaction may proceed according to the following reaction (10):

CO₂+C_(x)H_(y)→C_(x)H_(y-2)+CO+H₂O  (10)

wherein x is an integer and Y is 2x+2. Compositions useful in this regard include Fe₂O₃, Cr₂O₃, MnO₂, Ga₂O₃, Cr/SiO₂, Cr/SO₄—SiO₂, Cr—K/SO₄—SiO₂, Na₂WO₄—Mn/SiO₂, Cr-HZSM-5, Cr/Si-MCM-41 (Cr-HZSM-5 and Cr/Si-MCM-41 refer to known zeolites) and MoC/SiO₂. In some embodiments, any of the foregoing catalyst compositions may be supported on SiO₂, ZrO₂, Al₂O₃, TiO₂ or combinations thereof. In certain embodiments, the catalyst may be a nanowire catalyst and in other embodiments the catalyst is a bulk catalyst.

The catalysts having ODH activity with alternative oxygen sources (e.g., CO₂, referred to herein as a CO₂-ODH catalyst) have a number of advantages. For example, in some embodiments a method for converting methane to ethylene comprises use of an O₂-OCM catalyst in the presence of a CO₂-ODH catalyst is provided. Catalytic materials comprising at least one O₂-OCM catalyst and at least one CO₂-ODH catalyst are also provided in some embodiments. This combination of catalysts results in a higher yield of ethylene (and/or ratio of ethylene to ethane) since the CO₂ produced by the OCM reaction is consumed and used to convert ethane to ethylene.

In one embodiment, a method for preparation of ethylene comprises converting methane to ethylene in the presence of two or more catalysts, wherein at least one catalyst is an O₂-OCM catalyst and at least one catalyst is a CO₂-ODH catalyst. Such methods have certain advantages. For example, the CO₂-ODH reaction is endothermic and the O₂-OCM reaction is exothermic, and thus if the right mixture and/or arrangement of CO₂-ODH and O₂-OCM catalysts is used, the methods are particularly useful for controlling the exotherm of the OCM reaction. In some embodiments, the catalyst bed comprises a mixture of O₂-OCM catalyst and CO₂-ODH catalysts. The mixture may be in a ratio of 1:99 to 99:1. The two catalysts work synergistically as the O₂-OCM catalyst supplies the CO₂-ODH catalyst with the necessary carbon dioxide and the endothermic nature of the C2-OCM reaction serves to control the exotherm of the overall reaction.

Since the gas composition will tend to become enriched in CO₂ as it flows through the catalyst bed (i.e., as the OCM reaction proceeds, more CO₂ is produced), some embodiments of the present invention provide an OCM method wherein the catalyst bed comprises a gradient of catalysts which changes from a high concentration of O₂-OCM catalysts at the front of the bed to a high concentration of CO₂-ODH catalysts at the end of the catalyst bed.

The O₂-ODH catalyst and CO₂-ODH catalyst may have the same or different compositions. For example, in some embodiments the O₂-ODH catalyst and CO₂-ODH catalyst have the same composition but different morphologies (e.g., nanowire, bent nanowire, bulk, etc.). In other embodiments the O₂-ODH and the CO₂-ODH catalyst have different compositions.

In other embodiments, the catalyst bed comprises alternating layers of O₂-OCM and CO₂-ODH catalysts. The catalyst layer stack may begin with a layer of O₂-OCM catalyst, so that it can supply the next layer (e.g., a CO₂-ODH layer) with the necessary CO₂. The O₂-OCM layer thickness may be optimized to be the smallest at which O₂ conversion is 100% and thus the CH₄ conversion of the layer is maximized. The catalyst bed may comprise any number of catalyst layers, for example the overall number of layers may be optimized to maximize the overall CH₄ conversion and C2 selectivity.

In some embodiments, the catalyst bed comprises alternating layers of low temperature O₂-OCM catalysts and high temperature CO₂-ODH catalysts. Since the CO₂-ODH reaction is endothermic, the layers of CO₂-ODH catalyst may be sufficiently thin such that in can be “warmed up” by the hotspots of the O₂-OCM layers. The endothermic nature of the CO₂-ODH reaction can be advantageous for the overall thermal management of an OCM reactor. In some embodiments, the CO₂-ODH catalyst layers act as “internal” cooling for the O₂-OCM layers, thus simplifying the requirements for the cooling, for example in a tubular reactor. Therefore, an interesting cycle takes place with the endothermic reaction providing the necessary heat for the endothermic reaction and the endothermic reaction providing the necessary cooling for the exothermic reaction.

Accordingly, one embodiment of the present invention is a method for the oxidative coupling of methane, wherein the method comprises conversion of methane to ethane and/or ethylene in the presence of a catalytic material, and wherein the catalytic material comprises a bed of alternating layers of O₂-OCM catalysts and CO₂-ODH catalysts. In other embodiments the bed comprises a mixture (i.e., not alternating layers) of O₂-OCM catalysts and CO₂-ODH catalysts. Such methods increase the ethylene yield and/or ratio of ethylene to ethane compared to other known methods.

In other embodiments, the OCM methods include use of a jacketed reactor with the exothermic O₂-OCM reaction in the core and the endothermic CO₂-ODH reaction in the mantel. In other embodiments, the unused CO₂ can be recycled and reinjected into the reactor, optionally with the recycled CH₄. Additional CO₂ can also be injected to increase the overall methane conversion and help reduce greenhouse gases.

In other embodiments, the reactor comprises alternating stages of O₂-OCM catalyst beds and CO₂-ODH catalyst beds. The CO₂ necessary for the CO₂-ODH stages is provided by the O₂-OCM stage upstream. Additional CO₂ may also be injected. The O₂ necessary for the subsequent O₂-OCM stages is injected downstream from the CO₂-ODH stages. The CO₂-ODH stages may provide the necessary cooling for the O₂-OCM stages. Alternatively, separate cooling may be provided. Likewise, if necessary the inlet gas of the CO₂-ODH stages can be additionally heated, the CO₂-ODH bed can be heated or both.

In related embodiments, the CO₂ naturally occurring in natural gas is not removed prior to performing the OCM, alternatively CO₂ is added to the feed with the recycled methane. Instead the CO₂ containing natural gas is used as a feedstock for CO₂-ODH, thus potentially saving a separation step. The amount of naturally occurring CO₂ in natural gas depends on the well and the methods can be adjusted accordingly depending on the source of the natural gas.

3. Carbon Dioxide Reforming of Methane

Carbon dioxide reforming (CDR) of methane is an attractive process for converting CO₂ in process streams or naturally occurring sources into the valuable chemical product, syngas (a mixture of hydrogen and carbon monoxide). Syngas can then be manufactured into a wide range of hydrocarbon products through processes such as the Fischer-Tropsch synthesis (discussed below) to form liquid fuels including methanol, ethanol, diesel, and gasoline. The result is a powerful technique to not only remove CO₂ emissions but also create a new alternative source for fuels that are not derived from petroleum crude oil. The CDR reaction with methane is exemplified in reaction scheme (11).

CO₂+CH₄→2CO+2H₂  (11)

Unfortunately, no established industrial technology for CDR exists today in spite of its tremendous potential value. While not wishing to be bound by theory, it is thought that the primary problem with CDR is due to side-reactions from catalyst deactivation induced by carbon deposition via the Boudouard reaction (reaction scheme (12)) and/or methane cracking (reaction scheme (13)) resulting from the high temperature reaction conditions. The occurrence of the coking effect is intimately related to the complex reaction mechanism, and the associated reaction kinetics of the catalysts employed in the reaction.

2CO→C+CO₂  (12)

CH₄→C+2H₂  (13)

While not wishing to be bound by theory, the CDR reaction is thought to proceed through a multistep surface reaction mechanism. FIG. 9 schematically depicts a CDR reaction 700, in which activation and dissociation of CH₄ occurs on the metal catalyst surface 710 to form intermediate “M-C”. At the same time, absorption and activation of CO₂ takes place at the oxide support surface 720 to provide intermediate “S—CO₂”, since the carbon in a CO₂ molecule as a Lewis acid tends to react with the Lewis base center of an oxide. The final step is the reaction between the M-C species and the activated S—CO₂ to form CO.

In one embodiment, the present disclosure provides nanowires, for example the exemplary nanowires disclosed herein, which are useful as catalysts for the carbon dioxide reforming of methane. For example, in one embodiment the nanowires are useful as catalysts in a CDR reaction for the production of syn gas.

Improvements to the yield, selectivity, and/or conversion in the CDR reaction employing bulk catalysts are needed. Accordingly, in one embodiment, the nanowires posses a catalytic activity in the CDR reaction such that the yield, selectivity, and/or conversion is better than when the CDR reaction is catalyzed by a corresponding bulk catalyst. In one embodiment, the disclosure provides a nanowire having a catalytic activity such that the conversion of C002 to CO in the CDR reaction is greater than at least 1.1 times, 1.25 times, 1.50 times, 2.0 times, 3.0 times, or 4.0 times the conversion of CO₂ to CO compared to the same reaction under the same conditions but performed with a catalyst prepared from bulk material having the same chemical composition as the nanowire. In other embodiments, the conversion of CO₂ to CO in a CDR reaction catalyzed by the nanowire is greater than 10%, greater than 20%, greater than 30%, greater than 50%, greater than 75%, or greater than 90%.

In another embodiment, the disclosure provides a nanowire having a catalytic activity such that the yield of CO in a CDR reaction is greater than at least 1.1 times, 1.25 times, 1.50 times, 2.0 times, 3.0 times, or 4.0 times the yield of CO compared to the same reaction under the same conditions but performed with a catalyst prepared from bulk material having the same chemical composition as the nanowire. In some embodiments the yield of CO in a CDR reaction catalyzed by the nanowire is greater than 10%, greater than 20%, greater than 30%, greater than 50%, greater than 75%, or greater than 90%.

In another embodiment, the disclosure provides a nanowire having a catalytic activity in a CDR reaction such that the nanowire has the same or better catalytic activity, but at a lower temperature, compared a catalyst prepared from bulk material having the same chemical composition as the nanowire. In some embodiments the catalytic activity of the nanowires in a CDR reaction is the same or better than the catalytic activity of a catalyst prepared from bulk material having the same chemical composition as the nanowire, but at a temperature of at least 20° C. less. In some embodiments the catalytic activity of the nanowires in a CDR reaction is the same or better than the catalytic activity of a catalyst prepared from bulk material having the same chemical composition as the nanowire, but at a temperature of at least 50° C. less. In some embodiments the catalytic activity of the nanowires in a CDR reaction is the same or better than the catalytic activity of a catalyst prepared from bulk material having the same chemical composition as the nanowire, but at a temperature of at least 100° C. less. In some embodiments the catalytic activity of the nanowires in a CDR reaction is the same or better than the catalytic activity of a catalyst prepared from bulk material having the same chemical composition as the nanowire, but at a temperature of at least 200° C. less.

In another embodiment, the disclosure provides a nanowire having a catalytic activity such that the selectivity for CO in a CDR reaction is greater than at least 1.1 times, 1.25 times, 1.50 times, 2.0 times, 3.0 times, or 4.0 times the selectivity for CO compared to the same reaction under the same conditions but performed with a catalyst prepared from bulk material having the same chemical composition as the nanowire. In other embodiments, the selectivity for CO in a CDR reaction catalyzed by the nanowire is greater than 10%, greater than 20%, greater than 30%, greater than 50%, greater than 75%, or greater than 90%.

In one embodiment, the nanowires disclosed herein enable efficient conversion of CO₂ to CO in the CDR reaction at temperatures less than when the corresponding bulk material is used as a catalyst. For example, in one embodiment, the nanowires enable efficient conversion (i.e., high yield, conversion, and/or selectivity) of CO₂ to CO at temperatures of less than 900° C., less than 800° C., less than 700° C., less than 600° C., or less than 500° C.

4. Fischer-Tropsch Synthesis

Fischer-Tropsch synthesis (FTS) is a valuable process for converting synthesis gas (i.e., CO and H₂) into valuable hydrocarbon fuels, for example, light alkenes, gasoline, diesel fuel, etc. FTS has the potential to reduce the current reliance on the petroleum reserve and take advantage of the abundance of coal and natural gas reserves. Current FTS processes suffer from poor yield, selectivity, conversion, catalyst deactivation, poor thermal efficiency and other related disadvantages. Production of alkanes via FTS is shown in reaction scheme (14), wherein n is an integer.

CO+2H₂→(1/n)(C_(n)H_(2n))+H₂O  (14)

In one embodiment, nanowires are provided which are useful as catalysts in FTS processes. For example, in one embodiment the nanowires are useful as catalysts in a FTS process for the production of alkanes.

Improvements to the yield, selectivity, and/or conversion in FTS processes employing bulk catalysts are needed. Accordingly, in one embodiment, the nanowires posses a catalytic activity in an FTS process such that the yield, selectivity, and/or conversion is better than when the FTS process is catalyzed by a corresponding bulk catalyst. In one embodiment, the disclosure provides a nanowire having a catalytic activity such that the conversion of CO to alkane in an FTS process is greater than at least 1.1 times, 1.25 times, 1.50 times, 2.0 times, 3.0 times, or 4.0 times the conversion of CO to alkane compared to the same reaction under the same conditions but performed with a catalyst prepared from bulk material having the same chemical composition as the nanowire. In other embodiments, the conversion of CO to alkane in an FTS process catalyzed by the nanowire is greater than 10%, greater than 20%, greater than 30%, greater than 50%, greater than 75%, or greater than 90%.

In another embodiment, the disclosure provides a nanowire having a catalytic activity in an FTS process such that the nanowire has the same or better catalytic activity, but at a lower temperature, compared a catalyst prepared from bulk material having the same chemical composition as the nanowire. In some embodiments the catalytic activity of the nanowires in an FTS process is the same or better than the catalytic activity of a catalyst prepared from bulk material having the same chemical composition as the nanowire, but at a temperature of at least 20° C. less. In some embodiments the catalytic activity of the nanowires in an FTS process is the same or better than the catalytic activity of a catalyst prepared from bulk material having the same chemical composition as the nanowire, but at a temperature of at least 50° C. less. In some embodiments the catalytic activity of the nanowires in an FTS process is the same or better than the catalytic activity of a catalyst prepared from bulk material having the same chemical composition as the nanowire, but at a temperature of at least 100° C. less. In some embodiments the catalytic activity of the nanowires in an FTS process is the same or better than the catalytic activity of a catalyst prepared from bulk material having the same chemical composition as the nanowire, but at a temperature of at least 200° C. less.

In another embodiment, the disclosure provides a nanowire having a catalytic activity such that the yield of alkane in a FTS process is greater than at least 1.1 times, 1.25 times, 1.50 times, 2.0 times, 3.0 times, or 4.0 times the yield of alkane compared to the same reaction under the same conditions but performed with a catalyst prepared from bulk material having the same chemical composition as the nanowire. In some embodiments the yield of alkane in an FTS process catalyzed by the nanowire is greater than 10%, greater than 20%, greater than 30%, greater than 50%, greater than 75%, or greater than 90%.

In another embodiment, the disclosure provides a nanowire having a catalytic activity such that the selectivity for alkanes in an FTS process is greater than at least 1.1 times, 1.25 times, 1.50 times, 2.0 times, 3.0 times, or 4.0 times the selectivity for alkanes compared to the same reaction under the same conditions but performed with a catalyst prepared from bulk material having the same chemical composition as the nanowire. In other embodiments, the selectivity for alkanes in an FTS process catalyzed by the nanowire is greater than 10%, greater than 20%, greater than 30%, greater than 50%, greater than 75%, or greater than 90%.

In one embodiment, the nanowires disclosed herein enable efficient conversion of CO to alkanes in a CDR process at temperatures less than when the corresponding bulk material is used as a catalyst. For example, in one embodiment, the nanowires enable efficient conversion (i.e., high yield, conversion, and/or selectivity) of CO to alkanes at temperatures of less than 400° C., less than 300° C., less than 250° C., less than 200° C., less the 150° C., less than 100° C. or less than 50° C.

5. Oxidation of CO

Carbon monoxide (CO) is a toxic gas and can convert hemoglobin to carboxyhemoglobin resulting in asphyxiation. Dangerous levels of CO can be reduced by oxidation of CO to CO₂ as shown in reaction scheme 15:

CO+½O₂→CO₂  (15)

Catalysts for the conversion of CO into CO₂ have been developed but improvements to the known catalysts are needed. Accordingly in one embodiment, the present disclosure provides nanowires useful as catalysts for the oxidation of CO to CO₂.

In one embodiment, the nanowires posses a catalytic activity in a process for the conversion of CO into CO₂ such that the yield, selectivity, and/or conversion is better than when the oxidation of CO into CO₂ is catalyzed by a corresponding bulk catalyst. In one embodiment, the disclosure provides a nanowire having a catalytic activity such that the conversion of CO to CO₂ is greater than at least 1.1 times, 1.25 times, 1.50 times, 2.0 times, 3.0 times, or 4.0 times the conversion of CO to CO₂ compared to the same reaction under the same conditions but performed with a catalyst prepared from bulk material and having the same chemical composition as the nanowire. In other embodiments, the conversion of CO to CO₂ catalyzed by the nanowire is greater than 10%, greater than 20%, greater than 30%, greater than 50%, greater than 75%, or greater than 90%.

In another embodiment, the disclosure provides a nanowire having a catalytic activity such that the yield of CO₂ from the oxidation of CO is greater than at least 1.1 times, 1.25 times, 1.50 times, 2.0 times, 3.0 times, or 4.0 times the yield of CO₂ compared to the same reaction under the same conditions but performed with a catalyst prepared from bulk material having the same chemical composition as the nanowire. In some embodiments the yield of CO₂ from the oxidation of CO catalyzed by the nanowire is greater than 10%, greater than 20%, greater than 30%, greater than 50%, greater than 75%, or greater than 90%.

In another embodiment, the disclosure provides a nanowire having a catalytic activity in an oxidation of CO reaction such that the nanowire has the same or better catalytic activity, but at a lower temperature, compared a catalyst prepared from bulk material having the same chemical composition as the nanowire. In some embodiments the catalytic activity of the nanowires in an oxidation of CO reaction is the same or better than the catalytic activity of a catalyst prepared from bulk material having the same chemical composition as the nanowire, but at a temperature of at least 20° C. less. In some embodiments the catalytic activity of the nanowires in an oxidation of CO reaction is the same or better than the catalytic activity of a catalyst prepared from bulk material having the same chemical composition as the nanowire, but at a temperature of at least 50° C. less. In some embodiments the catalytic activity of the nanowires in an oxidation of CO reaction is the same or better than the catalytic activity of a catalyst prepared from bulk material having the same chemical composition as the nanowire, but at a temperature of at least 100° C. less. In some embodiments the catalytic activity of the nanowires in an oxidation of CO reaction is the same or better than the catalytic activity of a catalyst prepared from bulk material having the same chemical composition as the nanowire, but at a temperature of at least 200° C. less.

In another embodiment, the disclosure provides a nanowire having a catalytic activity such that the selectivity for CO₂ in the oxidation of CO is greater than at least 1.1 times, 1.25 times, 1.50 times, 2.0 times, 3.0 times, or 4.0 times the selectivity for CO₂ compared to the same reaction under the same conditions but performed with a catalyst prepared from bulk material having the same chemical composition as the nanowire. In other embodiments, the selectivity for CO₂ in the oxidation of CO catalyzed by the nanowire is greater than 10%, greater than 20%, greater than 30%, greater than 50%, greater than 75%, or greater than 90%.

In one embodiment, the nanowires disclosed herein enable efficient conversion of CO to CO₂ at temperatures less than when the corresponding bulk material is used as a catalyst. For example, in one embodiment, the nanowires enable efficient conversion (i.e., high yield, conversion, and/or selectivity) of CO to CO₂ at temperatures of less than 500° C., less than 400° C., less than 300° C., less than 200° C., less than 100° C., less than 50° C. or less than 20° C.

Although various reactions have been described in detail, the disclosed nanowires are useful as catalysts in a variety of other reactions. In general, the disclosed nanowires find utility in any reaction utilizing a heterogeneous catalyst and have a catalytic activity such that the yield, conversion, and/or selectivity in reaction catalyzed by the nanowires is better than the yield, conversion and/or selectivity in the same reaction catalyzed by a corresponding bulk catalyst.

6. Combustion of Hydrocarbons

In another embodiment, the present disclosure provides a nanowire having catalytic activity in a reaction for the catalyzed combustion of hydrocarbons. Such catalytic reactions find utility in catalytic converters for automobiles, for example by removal of unburned hydrocarbons in the exhaust by catalytic combustion or oxidation of soot captured on catalyzed particle filters resulting in reduction on diesel emissions from the engine. When running “cold”, the exhausts temperature of a diesel engine is quite low, thus a low temperature catalyst, such as the disclosed nanowires, is needed to efficiently eliminate all unburned hydrocarbons. In addition, in case of soot removal on catalyzed particulate filters, intimate contact between the soot and the catalyst is require; the open mesh morphology of nanowire catalyst coating is advantageous to promote such intimate contact between soot and oxidation catalyst.

In contrast to a corresponding bulk catalyst, Applicants have found that certain nanowires, for example the exemplary nanowires disclosed herein, posses a catalytic activity (for example because of their morphology) in the combustion of hydrocarbons such that the yield, selectivity, and/or conversion is better than when the combustion of hydrocarbons is catalyzed by a corresponding bulk catalyst. In one embodiment, the disclosure provides a nanowire having a catalytic activity such that the combustion of hydrocarbons or soot is greater than at least 1.1 times, 1.25 times, 1.50 times, 2.0 times, 3.0 times, or 4.0 times the combustion of hydrocarbons or soot compared to the same reaction under the same conditions but performed with a catalyst prepared from bulk material having the same chemical composition as the nanowire. In other embodiments, the total combustion of hydrocarbons or soot catalyzed by the nanowire is greater than 10%, greater than 20%, greater than 30%, greater than 50%, greater than 75%, or greater than 90%.

In another embodiment, the disclosure provides a nanowire having a catalytic activity such that the yield of combusted hydrocarbon products is greater than at least 1.1 times, 1.25 times, 1.50 times, 2.0 times, 3.0 times, or 4.0 times the yield of combusted hydrocarbon products compared to the same reaction under the same conditions but performed with a catalyst prepared from bulk material having the same chemical composition as the nanowire. In some embodiments the yield of combusted hydrocarbon products in a reaction catalyzed by the nanowire is greater than 10%, greater than 20%, greater than 30%, greater than 50%, greater than 75%, or greater than 90%.

The stability of the nanowires is defined as the length of time a catalyst will maintain its catalytic performance without a significant decrease in performance (e.g., a decrease >20%, >15%, >10%, >5%, or greater than 1% in hydrocarbon or soot combustion activity). In some embodiments, the nanowires have stability under conditions required for the hydrocarbon combustion reaction of >1 hr, >5 hrs, >10 hrs, >20 hrs, >50 hrs, >80 hrs, >90 hrs, >100 hrs, >150 hrs, >200 hrs, >250 hrs, >300 hrs, >350 hrs, >400 hrs, >450 hrs, >500 hrs, >550 hrs, >600 hrs, >650 hrs, >700 hrs, >750 hrs, >800 hrs, >850 hrs, >900 hrs, >950 hrs, >1,000 hrs, >2,000 hrs, >3,000 hrs, >4,000 hrs, >5,000 hrs, >6,000 hrs, >7,000 hrs, >8,000 hrs, >9,000 hrs, >10,000 hrs, >11,000 hrs, >12,000 hrs, >13,000 hrs, >14,000 hrs, >15,000 hrs, >16,000 hrs, >17,000 hrs, >18,000 hrs, >19,000 hrs, >20,000 hrs, >1 yrs, >2 yrs, >3 yrs, >4 yrs or >5 yrs.

In another embodiment, the disclosure provides a nanowire having a catalytic activity in the combustion of hydrocarbons such that the nanowire has the same or better catalytic activity, but at a lower temperature, compared a catalyst prepared from bulk material having the same chemical composition as the nanowire. In some embodiments the catalytic activity of the nanowires in the combustion of hydrocarbons is the same or better than the catalytic activity of a catalyst prepared from bulk material having the same chemical composition as the nanowire, but at a temperature of at least 20° C. less. In some embodiments the catalytic activity of the nanowires in the combustion of hydrocarbons is the same or better than the catalytic activity of a catalyst prepared from bulk material having the same chemical composition as the nanowire, but at a temperature of at least 50° C. less. In some embodiments the catalytic activity of the nanowires in the combustion of hydrocarbons is the same or better than the catalytic activity of a catalyst prepared from bulk material having the same chemical composition as the nanowire, but at a temperature of at least 100° C. less. In some embodiments the catalytic activity of the nanowires in the combustion of hydrocarbons is the same or better than the catalytic activity of a catalyst prepared from bulk material having the same chemical composition as the nanowire, but at a temperature of at least 200° C. less.

7. Evaluation of Catalytic Properties

To evaluate the catalytic properties of the nanowires in a given reaction, for example those reactions discussed above, various methods can be employed to collect and process data including measurements of the kinetics and amounts of reactants consumed and the products formed. In addition to allowing for the evaluation of the catalytic performances, the data can also aid in designing large scale reactors, experimentally validating models and optimizing the catalytic process.

One exemplary methodology for collecting and processing data is depicted in FIG. 10. Three main steps are involved. The first step (block 750) comprises the selection of a reaction and catalyst. This influences the choice of reactor and how it is operated, including batch, flow, etc. (block 754). Thereafter, the data of the reaction are compiled and analyzed (block 760) to provide insights to the mechanism, rates and process optimization of the catalytic reaction. In addition, the data provide useful feedbacks for further design modifications of the reaction conditions. Additional methods for evaluating catalytic performance in the laboratory and industrial settings are described in, for example, Bartholomew, C. H. et al. Fundamentals of Industrial Catalytic Processes, Wiley-AIChE; 2Ed (1998).

As an example, in a laboratory setting, an Altamira Benchcat 200 can be employed using a 4 mm ID diameter quartz tube with a 0.5 mm ID capillary downstream. Quartz tubes with 2 mm or 6 mm ID can also be used. Nanowires are tested in a number of different dilutions and amounts. In some embodiments, the range of testing is between 10 and 300 mg. In some embodiments, the nanowires are diluted with a non-reactive diluent. This diluent can be quartz (SiO₂) or other inorganic materials, which are known to be inert in the reaction condition. The purpose of the diluent is to minimize hot spots and provide an appropriate loading into the reactor. In addition, the catalyst can be blended with less catalytically active components as described in more detail above.

In a typical procedure, 50 mg is the total charge of nanowire, optionally including diluent. On either side of the nanowires a small plug of glass wool is loaded to keep the nanowires in place. A thermocouple is placed on the inlet side of the nanowire bed into the glass wool to get the temperature in the reaction zone. Another thermocouple can be placed on the downstream end of the nanowire bed into the catalyst bed itself to measure the exotherms, if any.

When blending the pure nanowire with diluent, the following exemplary procedure may be used: x (usually 10-50) mg of the catalyst (either bulk or test nanowire catalyst) is blended with (100-x) mg of diluent. Thereafter, about 2 ml of ethanol or water is added to form a slurry mixture, which is then sonicated for about 10 minutes. The slurry is then dried in an oven at about 100-140° C. for 2 hours to remove solvent. The resulting solid mixture is then scraped out and loaded into the reactor between the plugs of quartz wool.

Once loaded into the reactor, the reactor is inserted into the Altamira instrument and furnace and then a temperature and flow program is started. In some embodiment, the total flow is 50 to 100 sccm of gases but this can be varied and programmed with time. In one embodiment, the temperatures range from 450° C. to 900° C. The reactant gases comprise air or oxygen (diluted with nitrogen or argon) and methane in the case of the OCM reaction and gas mixtures comprising ethane and/or propane with oxygen for oxidative dehydrogenation (ODH) reactions. Other gas mixtures can be used for other reactions.

The primary analysis of these oxidation catalysis runs is the Gas Chromatography (GC) analysis of the feed and effluent gases. From these analyses, the conversion of the oxygen and alkane feed gases can easily be attained and estimates of yields and selectivities of the products and by-products can be determined.

The GC method developed for these experiments employs 4 columns and 2 detectors and a complex valve switching system to optimize the analysis. Specifically, a flame ionization detector (FID) is used for the analysis of the hydrocarbons only. It is a highly sensitive detector that produces accurate and repeatable analysis of methane, ethane, ethylene, propane, propylene and all other simple alkanes and alkenes up to five carbons in length and down to ppm levels.

There are two columns in series to perform this analysis, the first is a stripper column (alumina) which traps polar materials (including the water by-product and any oxygenates generated) until back-flushed later in the cycle. The second column associated with the FID is a capillary alumina column known as a PLOT column, which performs the actual separation of the light hydrocarbons. The water and oxygenates are not analyzed in this method.

For the analysis of the light non-hydrocarbon gases, a Thermal Conductivity Detector (TCD) may be employed which also employees two columns to accomplish its analysis. The target molecules for this analysis are CO₂, ethylene, ethane, hydrogen, oxygen, nitrogen, methane and CO. The two columns used here are a porous polymer column known as the Hayes Sep N, which performs some of the separation for the CO₂, ethylene and ethane. The second column is a molecular sieve column, which uses size differentiation to perform the separation. It is responsible for the separation of H₂, O₂, N₂, methane and CO.

There is a sophisticated and timing sensitive switching between these two columns in the method. In the first 2 minutes or so, the two columns are operating in series but at about 2 minutes, the molecular sieve column is by-passed and the separation of the first 3 components is completed. At about 5-7 minutes, the columns are then placed back in series and the light gases come off of the sieve according to their molecular size.

The end result is an accurate analysis of all of the aforementioned components from these fixed-bed, gas phase reactions. Analysis of other reactions and gases not specifically described above can be performed in a similar manner.

8. Downstream Products

As noted above, in one embodiment the present disclosure is directed to nanowires useful as catalysts in reactions for the preparation of a number of valuable hydrocarbon compounds. For example, in one embodiment the nanowires are useful as catalysts for the preparation of ethylene from methane via the OCM reaction. In another embodiment, the nanowires are useful as catalysts for the preparation of ethylene or propylene via oxidative dehydrogenation of ethane or propane, respectively. Ethylene and propylene are valuable compounds, which can be converted into a variety of consumer products. For example, as shown in FIG. 11, ethylene can be converted into many various compounds including low density polyethylene, high density polyethylene, ethylene dichloride, ethylene oxide, ethylbenzene, linear alcohols, vinyl acetate, alkanes, alpha olefins, various hydrocarbon-based fuels, ethanol and the like. These compounds can then be further processed using methods well known to one of ordinary skill in the art to obtain other valuable chemicals and consumer products (e.g. the downstream products shown in FIG. 11). Propylene can be analogously converted into various compounds and consumer goods including polypropylenes, propylene oxides, propanol, and the like.

Accordingly, in one embodiment the disclosure provides a method of preparing the downstream products of ethylene noted in FIG. 11. The method comprises converting ethylene into a downstream product of ethylene, wherein the ethylene has been prepared via a catalytic reaction employing a nanowire, for example any of the nanowires disclosed herein. In another embodiment the disclosure provides a method of preparing low density polyethylene, high density polyethylene, ethylene dichloride, ethylene oxide, ethylbenzene, ethanol or vinyl acetate from ethylene, wherein the ethylene has been prepared as described above.

In another embodiment, the disclosure provides a method of preparing a product comprising low density polyethylene, high density polyethylene, ethylene dichloride, ethylene oxide, ethylbenzene, ethanol or vinyl acetate, alkenes, alkanes, aromatics, alcohols, or mixtures thereof. The method comprises converting ethylene into low density polyethylene, high density polyethylene, ethylene dichloride, ethylene oxide, ethylbenzene, ethanol or vinyl acetate, wherein the ethylene has been prepared via a catalytic reaction employing a nanowires, for example any of the exemplary nanowires disclosed herein.

In more specific embodiments of any of the above methods, the ethylene is produced via an OCM or ODH reaction or combinations thereof.

In one particular embodiment, the disclosure provides a method of preparing a downstream product of ethylene and/or ethane, wherein the downstream product is a hydrocarbon fuel. For example, the downstream product of ethylene may be a C₄-C₁₄ hydrocarbon, including alkanes, alkenes and aromatics. Some specific examples include 1-butene, 1-hexene, 1-octene, xylenes and the like. The method comprises converting methane into ethylene, ethane or combinations thereof by use of a catalytic nanowire, for example any of the catalytic nanowires disclosed herein, and further oligomerizing the ethylene and/or ethane to prepare a downstream product of ethylene and/or ethane. For example, the methane may be converted to ethylene, ethane or combinations thereof via the OCM reaction as discussed above. The catalytic nanowire may be any nanowire and is not limited with respect to morphology or composition. The catalytic nanowire may be an inorganic catalytic polycrystalline nanowire, the nanowire having a ratio of effective length to actual length of less than one and an aspect ratio of greater than ten as measured by TEM in bright field mode at 5 keV, wherein the nanowire comprises one or more elements from any of Groups 1 through 7, lanthanides, actinides or combinations thereof. Alternatively, the catalytic nanowire may be an inorganic nanowire comprising one or more metal elements from any of Groups 1 through 7, lanthanides, actinides or combinations thereof and a dopant comprising a metal element, a semi-metal element, a non-metal element or combinations thereof. The nanowires may additionally comprise any number of doping elements as discussed above.

As depicted in FIG. 21, the method begins with charging methane (e.g., as a component in natural gas) into an OCM reactor. The OCM reaction may then be performed utilizing a nanowire under any variety of conditions. Water and CO₂ are optionally removed from the effluent and unreacted methane is recirculated to the OCM reactor.

Ethylene is recovered and charged to an oligomerization reactor. Optionally the ethylene stream may contain CO₂, H₂O, N₂, ethane, C3's and/or higher hydrocarbons. Oligomerization to higher hydrocarbons (e.g., C₄-C₁₄) then proceeds under any number of conditions known to those of skill in the art. For example oligomerization may be effected by use of any number of catalysts known to those skilled in the art. Examples of such catalysts include catalytic zeolites, crystalline borosilicate molecular sieves, homogeneous metal halide catalysts, Cr catalysts with pyrrole ligands or other catalysts. Exemplary methods for the conversion of ethylene into higher hydrocarbon products are disclosed in the following references: Catalysis Science & Technology (2011), 1(1), 69-75; Coordination Chemistry Reviews (2011), 255(7-8), 861-880; Eur. Pat. Appl. (2011), EP 2287142 A1 20110223; Organometallics (2011), 30(5), 935-941; Designed Monomers and Polymers (2011), 14(1), 1-23; Journal of Organometallic Chemistry 689 (2004) 3641-3668; Chemistry-A European Journal (2010), 16(26), 7670-7676; Acc. Chem. Res. 2005, 38, 784-793; Journal of Organometallic Chemistry, 695 (10-11): 1541-1549 May 15, 2010; Catalysis Today Volume 6, Issue 3, January 1990, Pages 329-349; U.S. Pat. Nos. 5,968,866; 6,800,702; 6,521,806; 7,829,749; 7,867,938; 7,910,670; 7,414,006 and Chem. Commun., 2002, 858-859, each of which are hereby incorporated in their entirety by reference.

In certain embodiments, the exemplary OCM and oligomerization modules depicted in FIG. 21 may be adapted to be at the site of natural gas production, for example a natural gas field. Thus the natural gas can be efficiently converted to more valuable and readily transportable hydrocarbon commodities without the need for transport of the natural gas to a processing facility.

Referring to FIG. 21, “natural gasoline” refers to a mixture of oligomerized ethylene products. The mixture may comprise 1-hexene, 1-octene, linear, branched or cyclic alkanes of 6 or more hydrocarbons, linear, branched, or cyclic alkenes of 6 or more hydrocarbons, aromatics, such as benzene, toluene, dimethyl benzene, xylenes, napthalene, or other oligomerized ethylene products and combinations thereof. This mixture finds particular utility in any number of industrial applications, for example natural gasoline is used as feedstock in oil refineries, as fuel blend stock by operators of fuel terminals, as diluents for heavy oils in oil pipelines and other applications. Other uses for natural gasoline are well-known to those of skill in the art.

EXAMPLES Example 1 Pechini Synthesis

Although any metal salt or combination of metal salts can be combined and processed using the Pechini method to prepare metal oxide catalysts, this example uses Ca, Nd, and Sr salts to prepare a mixed metal oxide OCM catalyst. Equimolar aqueous solutions of strontium nitrate, neodymium nitrate, and calcium nitrate were prepared. Aliquots of each solution were mixed together to prepare a desired formulation of Ca_(x)Nd_(y)Sr_(z) where x, y and z each independently represent mole fractions of total metal content in moles. Representative examples of formulations include, but are not limited to, Ca₅₀Nd₃₀Sr₂₀, Ca₅₂Nd₄₅Sr₀₅, Ca₇₅Nd₂₂Sr₀₃, and the like. A solution of citric acid was added to the metal salt mixture so that the citric acid mole/metal mole ratio was 3:1. Ethylene glycol (or any polyfunctional alcohol, for example glycerol or polyvinyl alcohol) was then added to the citric acid/metal salt solution so that the ethylene glycol/citric acid mole ratio was 1:1. The solution was stirred at room temperature for 1 h. The solution was placed in a 130° C. oven for 15 h to remove water and to promote resin formation. After 15 h, a hard dark resin was observed. The resin was placed in furnace and heated to 500° C. for 8 h. The remaining material was then heated to 650° C. for 2 h to yield the desired metal oxide product.

Example 2 Polymer Templated Synthesis

Dextran is a water-soluble polymer with a wide range of molecular weights and is a useful templating source. Briefly, a metal precursor and dextran are dissolved in water to produce a viscous solution. The solution is dried to make a metal organic composite and then calcined (oven or microwave) to remove the dextran template. Optionally, multiple metal precursors are dissolved in a dextran solution. Mixed metal oxide materials are readily prepared by dissolving different metal salts, in the desired ratio, in a viscous dextran solution. The solution is dried and calcined as described above to yield mixed metal oxide systems for OCM catalysis. Alternatively, freeze drying may be employed to dry the dextran/metal solution to prepare a more controllable porosity in the metal and mixed metal oxide materials.

Agarose is also used to prepare metal and mixed metal oxides for OCM catalysts. Agarose readily forms a gel that can be used as templating source by impregnating the gel with metal precursors. An agarose gel is impregnated with a metal precursor. Optionally the wet gel is impregnated with multiple metal precursors at the same time or step-wise for the eventual preparation of mixed metal oxide materials.

In an alternative to the above method, the metal-agarose composite is treated with a base to precipitate the metal precursors within the gel framework before calcination. Freeze drying is optionally used to remove the water from the metal-agarose composite. The agarose is removed by oven or microwave calcination to yield metal and mixed metal OCM catalysts.

Other catalysts are prepared according to the above methods employing any of the polymers and metal compositions disclosed herein.

Example 3 Preparation Mg(OH)₂ Nanowires

FIG. 11 shows a generic reaction scheme for preparing MgO nanowires (with dopant) via a polymer template. The reaction container can be anything from a small vial (for milliliter scale reactions) up to large bottles (for liter reaction scale reactions).

A magnesium solution and a base solution are added to the polymer solution in order to precipitate Mg(OH)₂. The magnesium solution can be of any soluble magnesium salt, e.g. MgX2.6H2O (X=Cl, Br, I), Mg(NO₃)₂, MgSO₄, magnesium acetate, etc. The range of the magnesium concentration in the reaction mixture is quite narrow, typically at 0.01M. The combination of the polymer concentration and the magnesium concentration (i.e. the ratio between the polymer and magnesium ions) can play a part in determining both the nanowires formation process window and their morphology.

The base can be any alkali metal hydroxide (e.g. LiOH, NaOH, KOH), soluble alkaline earth metal hydroxide (e.g. Sr(OH)₂, Ba(OH)₂) or any ammonium hydroxide (e.g., NR₄OH, R═H, CH₃, C₂H₅, etc.). Certain selection criteria for the base include: adequate solubility (at least several orders of magnitude higher than Mg(OH)₂ for Mg(OH)₂ nanowires), high enough strength (pH of the reaction mixture should be at least 11) and an inability to coordinate magnesium (for Mg(OH)₂ nanowires) to form soluble products. LiOH is a preferred choice for Mg(OH)₂ nanowires formation because lithium may additionally be incorporated in the Mg(OH)₂ as a dopant, providing a Li/MgO doped catalyst for OCM.

Another factor concerning the base is the amount of base used or the concentration ratio of OH⁻/Mg²⁺, i.e. the ratio between the number of OH equivalents added and the number of moles of Mg added. In order to fully convert the Mg ions in solution to Mg(OH)₂, the OH/Mg ratio needed is 2. The OH⁻/Mg²⁺ used in the formation of Mg(OH)₂ nanowires ranges from 0.5 to 2 and, depending on this ratio, the morphology of the reaction product changes from thin nanowires to agglomerations of nanoparticles. The OH⁻/Mg²⁺ ratio is determined by the pH of the reaction mixture, which needs to be at least 11. If the pH is below 11, no precipitation is observed, i.e. no Mg(OH)₂ is formed. If the pH is above 12, the morphology of the nanowires begins to change and more nanoparticles are obtained, i.e. non-selective precipitation.

Considering the narrow window of magnesium concentration in which Mg(OH)₂ nanowires can be obtained, the other key synthetic parameters that determine the nanowires formation and morphology include but are not limited to: polymer type and concentration thereof, the concentration ratio of Mg²⁺/polymer, the concentration ratio of OH⁻/Mg²⁺, the incubation time of polymer and Mg²⁺; incubation time of polymer and the OH⁻; the sequence of adding anion and metal ions; pH; the solution temperature in the incubation step and/or growth step; the types of metal precursor salt (e.g., MgCl₂ or Mg(NO₃)₂); the types of anion precursor (e.g., NaOH or LiOH); the number of additions; the time that lapses between the additions of the metal salt and anion precursor, including, e.g., simultaneous (zero lapse) or sequential additions.

The Mg salt solution and the base are added sequentially, separated by an incubation time (i.e., the first incubation time). The sequence of addition has an effect on the morphology of the nanowires. The first incubation time can be at least 1 h and it should be longer in the case the magnesium salt solution is added first. The Mg salt solution and the base can be added in a single “shot” or in a continuous slow flow using a syringe pump or in multiple small shots using a liquid dispenser robot. The reaction is then carried either unstirred or with only mild to moderate stirring for a specific time (i.e., the second incubation time). The second incubation time is not as strong a factor in the synthesis of Mg(OH)₂ nanowires, but it should be long enough for the nanowires to precipitate out of the reaction solution (e.g., several minutes). For practical reasons, the second incubation time can be as long as several hours. The reaction temperature can be anything from just above freezing temperature (e.g., 4° C.) up to 80° C. The temperature affects the nanowires morphology.

The precipitated Mg(OH)₂ nanowires are isolated by centrifuging the reaction mixture and decanting the supernatant. The precipitated material is then washed at least once with a water solution with pH>10 to avoid redissolution of the Mg(OH)₂ nanowires. Typically, the washing solution used can be ammonium hydroxide water solution or an alkali metal hydroxide solution (e.g., LiOH, NaOH, KOH). This mixture is centrifuged and the supernatant decanted. Finally, the product can be either dried (see, Example 5) or resuspended in ethanol for TEM analysis.

FIG. 11 depicts one embodiment for preparing Mg(OH)₂ nanowires. In a different embodiment, the order of addition may be reversed, for example in an exemplary 4 ml scale synthesis of Mg(OH)₂ nanowires and polymer are mixed in a 8 ml vial with 0.02 ml of 1 M LiOH aqueous solution and left incubating overnight (˜15 h). 0.04 ml of 1 M MgCl₂ aqueous solution are then added using a pipette and the mixture is mixed by gentle shaking. The reaction mixture is left incubating unstirred for 24 h. After the incubation time, the mixture is centrifuged, and the supernatant is decanted. The precipitated material is resuspended in 2 ml of 0.001 M LiOH aqueous solution (pH=11), the mixture is centrifuged and the supernatant decanted. The obtained Mg(OH)₂ nanowires are characterized by TEM as described in Example 4.

Example 4 Characterization of Mg(OH)₂ Nanowires

Mg(OH)₂ nanowires prepared according to Example 3 are characterized by TEM in order to determine their morphology. First, a few microliters (˜500) of ethanol is used to suspend the isolated Mg(OH)₂. The nanowires are then deposited on a TEM grid (copper grid with a very thin carbon layer) placed on filter paper to help wick out any extra liquid. After allowing the ethanol to dry, the TEM grid is loaded in a TEM and characterized. TEM is carried out at 5 KeV in bright field mode in a DeLong LVEM5.

The nanowires are additionally characterized by XRD (for phase identification) and TGA (for calcination optimization).

Example 5 Calcination of Mg(OH)₂ Nanowires

The isolated nanowires as prepared in Example 3 are dried in an oven at relatively low temperature (60-120° C.) prior to calcination.

The dried material is placed in a ceramic boat and calcined in air at 450 C° in order to convert the Mg(OH)₂ nanowires into MgO nanowires. The calcination recipe can be varied considerably. For example, the calcination can be done relatively quickly like in these two examples:

-   -   load in a muffle oven preheated at 450° C., calcination time=120         min     -   load in a muffle oven (or tube furnace) at room temperature and         ramp to 450° C. with 5° C./min rate, calcination time=60 min

Alternatively, the calcination can be done in steps that are chosen according to the TGA signals like in the following example:

-   -   load in a muffle oven (or tube furnace) at room temperature,         ramp to 100° C. with 2° C./min rate, dwell for 60 min, ramp to         280° C. with 2° C./min rate, dwell for 60 min, ramp to 350° C.         with 2° C./min rate, dwell for 60 min and finally ramp to         450° C. with 2° C./min rate, dwell for 60 min.

Generally, a step recipe is preferable since it should allow for a better, smoother and more complete conversion of Mg(OH)₂ into MgO. Optionally, the calcined product is ground into a fine powder.

Example 6 Preparation of Li Doped MgO Nanowires

Doping of nanowires is achieved by using the incipient wetness impregnation method. Before impregnating the MgO nanowires with the doping solution, the maximum wettability (i.e. the ability of the nanowires to absorb the doping solution before becoming a suspension or before “free” liquid is observed) of the nanowires is determined. This is a very important step for an accurate absorption of the doping metal on the MgO surface. If too much dopant solution is added and a suspension is formed, a significant amount of dopant will crystallize unabsorbed upon drying and if not enough dopant solution is added, significant portions of the MgO surface will not be doped.

In order to determine the maximum wettability of the MgO nanowires, small portions of water are dropped on the calcined MgO powder until a suspension is formed, i.e. until “free” liquid is observed. The maximum wettability is determined to be the total amount of water added before the suspension forms. The concentration of the doping solution is then calculated so that the desired amount of dopant is contained in the volume of doping solution corresponding to the maximum wettability of the MgO nanowires. In another way to describe the incipient wetness impregnation method, the volume of the doping solution is set to be equal to the pore volume of the nanowires, which can be determined by BET (Brunauer, Emmett, Teller) measurements. The doping solution is then drawn into the pores by capillary action.

In one embodiment, the doping metal for MgO based catalysts for OCM is lithium (see, also, FIG. 11). Thus, in one embodiment the dopant source can be any soluble lithium salt as long as it does not introduce undesired contaminants. Typically, the lithium salts used are LiNO₃, LiOH or Li₂CO₃. LiNO₃ and LiOH are preferred because of their higher solubility. In one embodiment, the lithium content in MgO catalysts for OCM ranges from 0 to 10 wt % (i.e. about 0 to 56 at %).

The calculated amount of dopant solution of the desired concentration is dropped onto the calcined MgO nanowires. The obtained wet powder is dried in an oven at relatively low temperature (60-120° C.) and calcined using one of the recipes described above. It is noted that, during this step, no phase transition occurs (MgO has already been formed in the previous calcination step) and thus a step recipe (see previous paragraph) may not be necessary.

The dopant impregnation step can also be done prior to the calcination, after drying the Mg(OH)₂ nanowires isolated from the reaction mixture. In this case, the catalyst can be calcined immediately after the dopant impregnation, i.e. no drying and second calcination steps would be required since its goals are accomplished during the calcination step.

Three identical syntheses are made in parallel. In each synthesis, 80 ml of concentrated polymer solution is mixed in a 100 ml glass bottle with 0.4 ml of 1 M LiOH aqueous solution and left incubating for 1 h. 0.8 ml of 1 M MgCl₂ aqueous solution are added using a pipette and the mixture is mixed by gently shaking it. The reaction mixture is left incubating unstirred for 72 h at 60° C. in an oven. After the incubation time, the mixture is centrifuged. The precipitated material is resuspended in 20 ml of 0.06 M NH₄OH aqueous solution (pH=11), the mixture is centrifuged and the supernatant decanted. The obtained Mg(OH)₂ nanowires are resuspended in ethanol. The ethanol suspensions of the three identical syntheses are combined and a few microliters of the ethanol suspension are used for TEM analysis. The ethanol suspension is centrifuged and the supernatant decanted. The gel-like product is transferred in a ceramic boat and dried for 1 h at 120° C. in a vacuum oven.

The dried product is calcined in a tube furnace using a step recipe (load in the furnace at room temperature, ramp to 100° C. with 2° C./min rate, dwell for 60 min, ramp to 280° C. with 2° C./min rate, dwell for 60 min, ramp to 350° C. with 2° C./min rate, dwell for 60 min, ramp to 450° C. with 2° C./min rate, dwell for 60 min and finally cool to room temperature). The calcined product is ground to a fine powder.

10 mg of the calcined product are impregnated with a LiOH aqueous solution. First, the maximum wettability is determined by adding water to the calcined product in a ceramic boat until the powder is saturated but no “free” liquid was observed. The maximum expected wettability is about 12 μl. Since the target doping level is 1 wt % lithium, the necessary concentration of the LiOH aqueous solution is calculated to be 1.2 M. The calcined product is dried again for 1 h at 120° C. to remove the water used to determine the wettability of the powder. 12 μl of the 1.2 M LiOH solution are dropped on the MgO nanowires powder. The wet powder is dried for 1 h at 120° C. in a vacuum oven and finally calcined in a muffle oven (load at room temperature, ramp to 460° C. with 2° C./min ramp, dwell for 120 min).

Example 7 OCM Catalyzed by La₂O₃ Nanowires

A 20 mg sample of a polymer-based Sr (5%) doped La₂O₃ catalyst is diluted with 80 mg of quartz sand and placed into a reactor (run WPS21). The gas flows are held constant at 9 sccm methane, 3 sccm oxygen and 6 sccm of argon. The upstream temperature (just above the bed) is varied from 500° C. to 800° C. in 100° C. increments and then decreased back down to 600° C. in 50° C. increments. The vent gas analysis is gathered at each temperature level.

The polymer-based nanowires according to the present disclosure are expected to comprise better OCM activity (i.e., conversion of methane, C2 selectivity, yield, etc.) compared to a corresponding bulk catalyst.

Example 8 Oxidative Dehydrogenation Catalyzed by MgO Nanowires

A 10 mg sample of polymer-based Li doped MgO catalyst is diluted with 90 mg of quartz sand and placed in a reactor. The gas flows are held constant at 8 sccm alkane mix, 2 sccm oxygen and 10 sccm of argon. The upstream temperature (just above the bed) is varied from 500° C. to 750° C. in 50-100° C. increments. The vent gas analysis is gathered at each temperature level.

The polymer-based nanowires according to the present disclosure are expected to comprise better conversion of ethane and propane compared to a corresponding bulk catalyst.

Example 9 Preparation of Sr Doped La₂O₃ Nanowires

Sr doped La₂O₃ nanowires are prepared according to the following method.

A 57 mg aliquot of La₂O₃ nanowires prepared as described herein is then mixed with 0.174 ml of a 0.1 M solution of Sr(NO₃)₂. This mixture is then stirred on a hot plate at 90° C. until a paste was formed.

The paste is then dried for 1 h at 120° C. in a vacuum oven and finally calcined in a muffle oven in air according to the following procedure: (1) load in the furnace at room temperature; (2) ramp to 200° C. with 3° C./min rate; (3) dwell for 120 min; (3) ramp to 400° C. with 3° C./min rate; (4) dwell for 120 min; (5) ramp to 500° C. with 3° C./min rate; and (6) dwell for 120 min. The calcined product is then ground to a fine powder.

Example 10 Preparation of La₂O₃ Nanowires

Two identical syntheses are made in parallel. In each synthesis, 360 ml of polymer solution are mixed in a 500 ml plastic bottle with 1.6 ml of 0.1 M LaCl₃ aqueous solution and left incubating for at least 1 hour. After this incubation period, a slow multistep addition is conducted with 20 ml of 0.1 M LaCl₃ solution and 40 ml of 0.3 M NH₄OH. This addition is conducted in 24 hours and 100 steps. The reaction mixture is left stirred for at least another hour at room temperature. After that time the suspension is centrifuged in order to separate the solid phase from the liquid phase. The precipitated material is then re-suspended in 25 ml of ethanol. The ethanol suspensions from the two identical syntheses are combined and centrifuged in order to remove un-reacted species. The gel-like product remaining is then dried for 15 hours at 65° C. in an oven and then calcined in a muffle oven in air (load in the furnace at room temperature, ramp to 100° C. with 2° C./min rate, dwell for 30 min, ramp to 400° C. with 2° C./min rate, dwell for 240 min, ramp to 550° C. with 2° C./min rate, dwell for 240 min, cool to room temperature).

Example 11 Preparation of Mg/Na Doped La₂O₃ Nanowires

Two identical syntheses are made in parallel. In each synthesis, 360 ml of polymer solution are mixed in a 500 ml plastic bottle with 1.6 ml of 0.1 M LaCl₃ aqueous solution and left incubating for at least 1 hour. After this incubation period, a slow multistep addition is conducted with 20 ml of 0.1 M LaCl₃ solution and 40 ml of 0.3 M NH₄OH. This addition is conducted in 24 hours and 100 steps. The reaction mixture is left stirred for at least another hour at room temperature. After that time, the suspension is centrifuged in order to separate the solid phase from the liquid phase. The precipitated material is then resuspended in 25 ml of ethanol. The ethanol suspensions from the two identical syntheses are combined and centrifuged in order to remove un-reacted species. The gel-like product remaining is then dried for 15 hours at 65° C. in an oven.

The target doping level is 20 at % Mg and 5 at % Na at % refers to atomic percent). 182 mg of the dried product are suspended in 2.16 ml deionized water, 0.19 ml 1 M Mg(NO₃)₂ aqueous solution and 0.05 ml 1M NaNO₃ aqueous solution. The resulting slurry is stirred at room temperature for 1 hour, sonicated for 5 min, then dried at 120° C. in and oven until the powder is fully dried and finally calcined in a muffle oven in air (load in the furnace at room temperature, ramp to 100° C. with 2° C./min rate, dwell for 30 min, ramp to 400° C. with 2° C./min rate, dwell for 60 min, ramp to 550° C. with 2° C./min rate, dwell for 60 min, ramp to 650° C. with 2° C./min rate, dwell for 60 min, ramp to 750° C. with 2° C./min rate, dwell for 240 min, cool to room temperature).

Example 12 Oxidative Coupling of Methane Catalyzed by Mg/Na Doped La₂O₃ Nanowires

50 mg of Mg/Na-doped La₂O₃ nanowires catalyst from example 12 are placed into a reactor tube (4 mm ID diameter quartz tube with a 0.5 mm ID capillary downstream), which is then tested in an Altamira Benchcat 203. The gas flows are held constant at 46 sccm methane and 54 sccm air, which correspond to a CH₄/O₂ ratio of 4 and a feed gas-hour space velocity (GHSV) of about 130000/hour. The reactor temperature is varied from 400° C. to 450° C. in a 50° C. increment, from 450° C. to 550° C. in 25° C. increments and from 550° C. to 750° C. in 50° C. increments. The vent gases are analyzed with gas chromatography (GC) at each temperature level.

In another example, 50 mg of Mg/Na-doped La₂O₃ nanowires catalyst from example 12 are placed into a reactor tube (4 mm ID diameter quartz tube with a 0.5 mm ID capillary downstream), which is then tested in an Altamira Benchcat 203. The gas flows are held constant at 46 sccm methane and 54 sccm air, which correspond to a feed gas-hour space velocity (GHSV) of about 130000 h⁻¹. The CH₄/O₂ ratio is 5.5. The reactor temperature is varied from 400° C. to 450° C. in a 50° C. increment, from 450° C. to 550° C. in a 25° C. increments and from 550° C. to 750° C. in 50° C. increments. The vent gases are analyzed with gas chromatography (GC) at each temperature level.

Example 13 Nanowire Synthesis

Nanowires may be prepared by hydrothermal synthesis from metal hydroxide gels (made from metal salt+base). In some embodiments, this method is applicable to lanthanides, for example La, Nd, Pr, Sm, Eu, and lanthanide containing mixed oxides.

Alternatively, nanowires can be prepared by synthesis from metal hydroxide gel (made from metal salt+base) under reflux conditions. In some embodiments, this method is applicable to lanthanides, for example La, Nd, Pr, Sm, Eu, and lanthanide containing mixed oxides.

Alternatively, the gel can be aged at room temperature. Certain embodiments of this method are applicable for making magnesium hydroxychloride nanowires, which can be converted to magnesium hydroxide nanowires and eventually to MgO nanowires. In a related method, hydrothermal treatment of the gel instead of aging is used.

Nanowires may also be prepared by polyethyleneglycol assisted hydrothermal synthesis. For example, Mn containing nanowires may be prepared according to this method using methods known to those skilled in the art. Alternatively, hydrothermal synthesis directly from the oxide can be used.

Example 14 Preparation of Nd₂O₃, Eu₂O₃ and Pr₂O₃ Nanowires

Three syntheses are made in parallel. In each synthesis, 10 ml of polymer solution are mixed in a 60 ml glass vial with 25 μl of 0.08M NdCl₃, EuCl₃ or PrCl₃ aqueous solutions, respectively and left incubating for at least 1 hour. After this incubation period, a slow multistep addition is conducted with 630 μl of 0.08M LaCl₃, EuCl₃ or PrCl₃ aqueous solutions, respectively and 500 μl of 0.3M NH₄OH. This addition is conducted in 33 hours and 60 steps. The reaction mixtures are left stirred for at least another 10 hour at room temperature. After that time the suspensions are centrifuged in order to separate the solid phase from the liquid phase. The precipitated material is then re-suspended in 4 ml of ethanol. The ethanol suspensions are centrifuged in order to finish removing un-reacted species. The gel-like product remaining is then dried for 1 hours at 65° C. in an oven and then calcined in a muffle oven in air (load in the furnace at room temperature, ramp to 100° C. with 2° C./min rate, dwell for 30 min, ramp to 500° C. with 2° C./min rate, dwell for 240 min, cool to room temperature). The obtained Nd(OH)₃, Eu(OH)₃ and Pr(OH)₃ nanowires were characterized by TEM before being dried.

Example 15 Preparation of Ce₂O₃/La₂O₃ Mixed Oxide Nanowires

In this synthesis, 15 ml of polymer are mixed in a 60 ml glass vial with 15 μl of 0.1M La(NO₃)₃ aqueous solution and left incubating for about 16 hour. After this incubation period, a slow multistep addition is conducted with 550 μl of 0.2M Ce(NO₃)₃ aqueous solution, 950 μl of 0.2M La(NO₃)₃ aqueous solution and 1500 μl of 0.4M NH₄OH. This addition is conducted in 39 hours and 60 steps. The reaction mixtures are left stirred for at least another 10 hours at room temperature. After that time the suspensions are centrifuged in order to separate the solid phase from the liquid phase. The precipitated material is then re-suspended in 4 ml of ethanol. The ethanol suspensions are centrifuged in order to finish removing un-reacted species. The gel-like product remaining is then dried for 1 hours at 65° C. in an oven and then calcined in a muffle oven in air (load in the furnace at room temperature, ramp to 100° C. with 2° C./min rate, dwell for 30 min, ramp to 500° C. with 2° C./min rate, dwell for 120 min, cool to room temperature).

Example 16 Oligomerization of Ethylene to Liquid Hydrocarbon Fuels with High Aromatics Content

0.1 g of the zeolite ZSM-5 is loaded into a fixed bed micro-reactor and heated at 400° C. for 2 h under nitrogen to activate the catalyst. The OCM effluent, containing ethylene and ethane, is reacted over the catalyst at 400° C. at a flow rate of 50 mL/min and GSHV=3000-10000 mL/(g h). The reaction products are separated into liquid and gas components using a cold trap. The gas and liquid components are analyzed by gas chromatography. C5-C10 hydrocarbon liquid fractions, such as xylene and isomers thereof, represent ≥90% of the liquid product ratio while the C11-C15 hydrocarbon fraction represents the remaining 10% of the product ratio.

Example 17 Oligomerization of Ethylene to Liquid Hydrocarbon Fuels with High Olefins Content

0.1 g of the zeolite ZSM-5 doped with nickel is loaded into a fixed bed micro-reactor and heated at 350° C. for 2 h under nitrogen to activate the catalyst. The OCM effluent, containing ethylene and ethane, is reacted over the catalyst at 250-400° C. temperature rage with GSHV=1000-10000 mL/(g h). The reaction products are separated into liquid and gas components using a cold trap. The gas and liquid components are analyzed by gas chromatography. C₄-C₁₀ olefin hydrocarbon liquid fractions, such as butene, hexane and octene represent ≥95% of the liquid product ratio while the C₁₂-C₁₈ hydrocarbon fraction represents the remaining 5% of the product ratio. Some trace amounts of odd numbered olefins are also possible in the product.

Example 18 OCM Catalyzed by La₂O₃ Nanowires

50 mg of a nanowire catalyst as described herein are placed into a reactor tube (4 mm ID diameter quartz tube with a 0.5 mm ID capillary downstream), which is then tested in an Altamira Benchcat 203. The gas flows are held constant at 46 sccm methane and 54 sccm air, which correspond to a CH₄/O₂ ratio of 4 and a feed gas-hour space velocity (GHSV) of about 130000/hour. The reactor temperature is varied from 400° C. to 500° C. in a 100° C. increment and from 500° C. to 850° C. in 50° C. increments. The vent gases are analyzed with gas chromatography (GC) at each temperature level.

Example 19 Preparation of Catalytic Material Comprising Cordierite Honeycomb Ceramic Supported Nd₂O₃ Nanowires

Nd₂O₃ nanowires are prepared in a manner analogous to those described herein.

A 400 mg aliquot of Nd₂O₃ nanowires is mixed with 2 g of DI water and placed into a 5 ml glass vial containing 2 mm Yttria Stabilized Zirconia milling balls. The vial is placed on a shaker at 2000 RPM and agitated for 30 minutes. A thick slurry is obtained.

A ⅜ inch diameter core is cut along the channel direction into a 400 CPSI (channel per square inch) cordierite honeycomb monolith and cut in length so the core volume is approximately 1 ml.

The core is placed into a ⅜ inch tube, and the catalyst slurry is fed on top of the ceramic core and pushed with compressed air through the monolith channel. The excess slurry is captured into a 20 ml vial. The coated core is removed from the ⅜ inch tube and placed into a drying oven at 200° C. for 1 hour.

The coating step is repeated twice more time with the remaining slurry followed by drying at 200° C. and calcination at 500° C. for 4 hours. The catalyst amount deposited on the monolith channel walls is approximately 50 mg and comprises very good adhesion to the ceramic wall.

Example 20 Preparation of Catalytic Material Comprising Silicon Carbide Ceramic Foam Supported Nd₂O₃ Nanowires

Nd₂O₃ nanowires are prepared in a manner analogous to the above examples.

A 400 mg aliquot of Nd₂O₃ nanowires is mixed with 2 g of DI water and placed into a 5 ml glass vial containing 2 mm Yttria Stabilized Zirconia milling balls. The vial is placed on a shaker at 2000 RPM and agitated for 30 minutes. A thick slurry is obtained.

A ⅜ inch diameter core is cut from a 65 PPI (Pore Per Inch) SiC foam and cut in length so the core volume is approximately 1 ml.

The core is placed into a ⅜ inch tube and the catalyst slurry is fed on top of the ceramic core and pushed with compressed air through the monolith channel. The excess slurry is captured into a 20 ml vial. The coated core is removed from the ⅜ inch tube and placed into a drying oven at 200° C. for 1 hour.

The coating step is repeated twice more time with the remaining slurry followed by drying at 200° C. and calcination at 500° C. for 4 hours. The catalyst amount deposited on the monolith channel walls is approximately 60 mg and comprises very good adhesion to the ceramic mesh.

Example 21 Preparation of Catalytic Material Comprising Silicon Carbide and Nd₂₀O₃ Nanowires

Nd₂O₃ nanowires are prepared in a manner analogous to the above examples

A 400 mg aliquot of Nd₂O₃ nanowires is dry blend mixed with 400 mg of 200-250 mesh SiC particles for 10 minutes or until the mixture appears homogeneous and wire clusters are no longer visible. The mixture is then placed into a ¼ inch die and pressed in 200 mg batches. The pressed pellets are then placed into an oven and calcined at 600° C. for 2 hours. The crush strength of the pellet obtained is comparable to the crush strength of a pellet made with only Nd₂O₃ nanowires.

Example 22 Preparation of Sr Doped La₂O₃ Nanowires

Sr doped La₂O₃ nanowires are prepared according to the following method.

A 57 mg aliquot of La₂O₃ nanowires prepared as described herein is then mixed with 0.174 ml of a 0.1 M solution of Sr(NO₃)₂. This mixture is then stirred on a hot plate at 90° C. until a paste was formed.

The paste is then dried for 1 h at 120° C. in a vacuum oven and finally calcined in a muffle oven in air according to the following procedure: (1) load in the furnace at room temperature; (2) ramp to 200° C. with 3° C./min rate; (3) dwell for 120 min; (3) ramp to 400° C. with 3° C./min rate; (4) dwell for 120 min; (5) ramp to 500° C. with 3° C./min rate; and (6) dwell for 120 min. The calcined product is then ground to a fine powder.

The various embodiments described above can be combined to provide further embodiments. All of the U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheet, are incorporated herein by reference, in their entirety. Aspects of the embodiments can be modified, if necessary to employ concepts of the various patents, applications and publications to provide yet further embodiments. These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure. 

1.-33. (canceled)
 34. A process for the preparation of ethylene from methane comprising contacting a mixture comprising oxygen and methane with a catalytic material comprising nanowires comprising a plurality of metal oxides (M_(x)O_(y)), metal oxy-hydroxides (M_(x)O_(y)OH_(z)), metal oxycarbonates (M_(x)O_(y)(CO₃)_(z)) or metal carbonates (M_(x)(CO₃)_(y)) or combinations thereof, the nanowires prepared by a method comprising: a) providing a solution comprising a polymer template; and (b) introducing at least one metal ion and at least one anion to the solution under conditions and for a time sufficient to allow for nucleation and growth of nanowires comprising a plurality of metal salts (M_(m)X_(n)Z_(p)) on the polymer template, wherein: M is, at each occurrence, independently a metal element from any of Groups 1 through 7, lanthanides or actinides; X is, at each occurrence, independently hydroxide, carbonate, bicarbonate, phosphate, hydrogenphosphate, dihydrogenphosphate, sulfate, nitrate or oxalate; Z is O; n, m, x and y are each independently a number from 1 to 100; and p is a number from 0 to
 100. 35. The process of claim 34, wherein the polymer template is functionalized with at least one of amine, carboxylic acid, sulfate, alcohol or thiol groups.
 36. The process of claim 35, wherein the polymer template comprises a hydrocarbon polymer.
 37. The process of claim 36, wherein the polymer template comprises polystyrene.
 38. The process of claim 34, wherein the method further comprises converting the nanowires comprising the plurality of metal salts (M_(m)X_(n)Z_(p)) to the nanowires comprising the plurality of metal oxides (M_(x)O_(y)), metal oxy-hydroxides (M_(x)O_(y)OH_(z)), metal oxycarbonates (M_(x)O_(y)(CO₃)_(z)), metal carbonate (M_(x)(CO₃)_(y)) or combinations thereof.
 39. The process of claim 34, further comprising oligomerizing the ethylene to prepare a downstream product of ethylene.
 40. The process of claim 34, where the preparation of ethylene is carried out at a temperature below 900° C.
 41. The process of claim 34, where the catalytic material comprises the nanowires with a C2 selectivity of greater than 50%.
 42. The process of claim 34, where the catalytic material comprises the nanowires with a methane conversion of greater than 20%.
 43. The process of claim 34, where the preparation of ethylene is carried out at a pressure greater than 6 atmospheres.
 44. A process for the preparation of ethylene from methane comprising contacting a mixture comprising oxygen and methane with a catalytic material comprising nanowires having catalytic activity for oxidative coupling of methane, the nanowires prepared by a method comprising: preparing an aqueous mixture comprising (A), (B) and (C) by: admixing (A) with a mixture comprising (B) and (C); admixing (B) with a mixture comprising (A) and (C); or admixing (C) with a mixture comprising (A) and (B), wherein (A), (B) and (C) comprise, respectively: (A) a polymer template; (B) two or more metal salts comprising two or more metal elements selected from Groups 1 through 7, lanthanides and actinides thereof, wherein the two or more metal elements are independently different elements selected from Groups 1 through 7, lanthanides and actinides; and (C) one or more anion precursors; and nucleating and growing the nanowires on the polymer template in the aqueous mixture.
 45. The process of claim 44, wherein the polymer template is functionalized with at least one of amine, carboxylic acid, sulfate, alcohol or thiol groups.
 46. The process of claim 45, wherein the polymer template comprises a hydrocarbon polymer.
 47. the process of claim 46, wherein the polymer template comprises polystyrene.
 48. The process of claim 44, further comprising oligomerizing the ethylene to prepare a downstream product of ethylene.
 49. The process of claim 44, wherein the preparation of ethylene is carried out at a temperature below 900° C.
 50. The process of claim 44, wherein the catalytic material comprises the nanowires with a C2 selectivity of greater than 50%.
 51. The process of claim 44, wherein the catalytic material comprises the nanowires with a methane conversion of greater than 20%.
 52. The process of claim 44, wherein the preparation of ethylene is carried out at a pressure greater than 6 atmospheres.
 53. The process of claim 44, wherein the mixture comprising (B) and (C) is prepared by admixing (B) and (C), the mixture comprising (A) and (C) is prepared by admixing (A) and (C) or the mixture comprising (A) and (B) is prepared by admixing (A) and (B).
 54. The process of claim 44, wherein the two or more metal salts comprise chlorides, bromides, iodides, nitrates, sulfates, acetates, oxides, oxalates, oxyhalides, oxynitrates, phosphates, hydrogenphosphate, dihydrogenphosphate or mixtures thereof.
 55. The process of claim 44, wherein the two or more salts comprise MgCl₂, LaCl₃, ZrCl₄, WCl₄, MoCl₄, MnCl₂ MnCl₃, Mg(NO₃)₂, La(NO₃)₃, ZrOCl₂, Mn(NO₃)₂, Mn(NO₃)₃, ZrO(NO₃)₂, Zr(NO₃)₄ or mixtures thereof.
 56. The process of claim 44, wherein the metals in the two or more metal salts are independently different metals selected from Mg, Ca, Mg, W, La, Nd, Sm, Eu, W, Mn and Zr.
 57. The process of claim 44, wherein the one or more anion precursors comprise alkali metal hydroxides, alkaline earth metal hydroxides, carbonates, bicarbonates, ammonium hydroxides, or mixtures thereof.
 58. The process of claim 44, wherein the one or more anion precursors comprise LiOH, NaOH, KOH, Sr(OH)₂, Ba(OH)₂, Na₂CO₃, K₂CO₃, NaHCO₃, KHCO₃, and NR₄OH, wherein R is selected from H, and C₁-C₆ alkyl.
 59. The process of claim 44, wherein the polymer template comprises PVP (polyvinlpyrrolidone), PVA (polyvinylalcohol), PEI (polyethyleneimine), PEG (polyethyleneglycol), polyethers, polyesters, polyamides, dextran, sugar polymers, functionalized hydrocarbon polymers, functionalized polystyrene, polylactic acid, polycaprolactone, polyglycolic acid, poly(ethylene glycol)-poly(propylene glycol)-poly(ethylene glycol) or copolymers or combinations thereof.
 60. The process of claim 44, wherein nucleating and growing the nanowires on the polymer template in the aqueous mixture comprises allowing the aqueous mixture comprising (A), (B) and (C) to stand at a temperature of from about 4° C. to about 80° C. for a period of time sufficient to allow nucleation of the nanowires.
 61. The process of claim 44, further comprising adding a doping element comprising metal elements, semi-metal elements, non-metal elements or combinations thereof to the aqueous mixture comprising (A), (B) and (C).
 62. The process of claim 44, further comprising calcining the nanowires.
 63. The process of claim 62, wherein calcining the nanowires comprises heating the nanowires at 450° C. or greater for at least 60 min. 